Mos

Objective Type Questions2.1. The ratio of shear stress to shear

strain within elastic limit is known 2.8.as(a) bulk modulus(b) shear modulus(c) Young's modulus(d) modulus of resilience.

2.2. When a bar is loaded uniaxially in 2.9. tension, the decrease in dimension occurs in(a) width only(b) thickness only(c) width and thickness both(d) all of the above.

2.3. The independent elastic constant of 2.10. an insotropic material are(a) 4 (b) 3(c) 2 (d) 1.

2.4. Total number of elastic constants of an insotropic material are(fl) 5 (b) 4 2 1 1 -(c) 3 (d) 2.

2.5. Colum n is a m em ber w hich is subjected to(a) axial tension(b) axial load(c) axial compression(d) both (a) and (b). 2.12.

2.6 . Strength of a material is mainly due to(a) atomic binding force(b) type of material(c) its use 2.13.(d) none of the above.

2.. The breaking stress of a material is lower than its(a) yield stress(b) working stress(c) ultimate stress 2.14.

(d) necking stress.The reciprocal of Young's modulus is called(a) coefficient of elasticity(b) Young's modulus constant(c) both of the above(d) none of the above.The shear stress x in thin cylindrical shell is expressed by

(a) t = (b) x = cSj/2

(c) x = a h/ 2 (d) X =

Domestic water supply pipeline is the example of(a) thin cylinder(b) thick cylinder(c) both of the above(d) none of the above.The longitudinal strain e/7 zh and evol for thin cylind rical shell are connected as

(fl) evoi = h + 2 8/(&) voi = h + e ;(c) evo| = 3e + 2e,(d) evol = 2b, + s;.The radius of gyration k is a(a) surface property(b) geometrical property(c) both of the above(d) none of the above.Analysis of long columns is made using(a) Rankine's theory(b) Euler's theory(c) Mohr's theory(d) All of the above.Column is a structural member of

2.60 Civil Engineering (Objective Type)

2.15.

2.16.

2.17.

2.18.

2.19.

2 .2 0 .

(a) 3-dimensional type(b) 2-dimensional type(c) zero-dimensional type(d ) 1-dimensional type.Rupture stress is(a) breaking stress(b) maximum load/original cross-

sectional area 2.21.(c) load at breaking point/original

cross-sectional area(d) load at breaking p oin t/n eck

area.The ratio of maximum shear stress develop in a solid shaft of diameter 2.22. D and a hollow shaft of external diameter D and internal diameter d for the same torque is given by

D*-

uncentrated epth of the then the

e beam will

/o.5 m long ends and

?ction with

ntensity in section is '3 '3.th L with d having

Strength o f Materials 2.61

ded freely ;ht. The i be

>f these.

lentors is ; Test ?


2.37.

2.38.

2.39.

2.40.

2 .4 1 .

(a) a v (b) a x(c) c t,/2 (d) a x/2 .Strain energy absorbed by a material is u, and V is the volume.The m odulus of resilience is 2.42.expressed as(a) u / V (b) u2/ V(c) uV (d) / V A beam subjected to B.M. of MY and of flexural rigidity El absorbs strain energy equal to

()

(b)

(c)

j.J (M * /2 E l)

|(Mv / 2EI)

dx

dx

J(M /E l) dx

(d) J(M ^ /4 E I )dx.o

Strain energy under sudden loading absorbed by a material in tension, as com pared to the same under gradual loading is(a) 3 times (b) 8 times(c) 4 times (d ) 2 times. 2.43.The strain energy absorbed by an element in a 2-dimensional planer biaxial tensile system will (o is Poisson's ratio and V the volume)

(a) (cti+ctj- 2 0 0 ^ 2) V

(b) -j E (a? + a ^ -2 o a 1CT2)V

( C) ( O i + C 2 UCT1CT2 ) V

(d) J E (af + a ^ -u a 1c 2) v .

Which of the following beams are indeterminate ?

(a) Cantilever(b) Continuous(c) Beam on elastic foundation(d) Both (b) and (c).Fig. 4 shows a channel section beam made up of thin rectangles. When

Fig. 4.area of web and the outstanding flange are A w and A^ respectively, the value of V will be

(a) e = AB

(b)

(c) e = -

(d) e -

h(A w/ 6 A f )\

AB

2 [l- (6 A w/ 6 A f )\

AB

AB1 (6A /A f )

2.44.

A beam is built-up of 1 mm thick aluminium alloy sheet bent into channel from. The need of finding shear centre(a) does not exist(b) exist(c) both of the above(d) none of the above.For a sem i-circular beam of thin section, the value of e. measured from the centre of circle of radius p is(a) p /4 71 (b) 4 7t/p(c) 4 p /71 (d) 4 7i p.


2.45.

2.46.

2.47.

2.48.

2.49.

2.50.

The elem ent of a m achine component is shown in Fig. 5. The maximum principle stress will be

3 kN/cm2

3 kN/cm25 kN/cm2

Fig. 5.

(a) 6 kN /cm 2 compressive(b) 6 kN /cm 2 tensile(c) 12 kN /cm 2 compressive(d ) 16 kN /cm 2 tensile.In above problem, the minimum principle stress will be(a) 4 kN /cm 2 compressive(b) 8 kN /cm 2 tensile(c) 4 kN /cm 2 compressive(d) 8 kN /m m 2 tensile.The m axim um shear stress in problem 2.45 will be {a) 1 kN /cm 2 (b) 2 kN /cm 2(c) 5 kN /cm 2 (d ) 10 k N /cm 2. Limit of proportionality and elastic limit points practically coincide in case of(a) lead and copper(b) steel and wrought iron(c) steel and copper(d) lead and steel.Tenacity means(a) tensile elastic stress(b) tensile yield stress(c) tensile working stress(d) tensile ultimate stress.In a tensile test, the order of the stages is(a) yield stress, breaking stress and

ultimate stress(b) yield stress, ultimate stress and

breaking stress

(c) ultimate stress, breaking stress and yield stress

(d) breaking stress, yield stress and ultimate stress.

2.51. If a ; is the elastic limit stress, CT2 is called(a) resilience(b) proof resilience(c) strain energy(d) modulus of resilience

2.52. The ratio betw een the stress produced by gradually applied and suddenly applied load is(a) 1 (b) 2(c) 1 /2 (d) none of these.

2.53. Impact stress is produced due to(a) suddenly applied load only(b) falling load only(c) suddenly applied and falling

load(d) gradually applied load.

2.54. The ratio of shear modulus to the modulus of elasticity for a Poisson's ratio of 0.4 will be(a) 5 /7 (b) 7 /5(c) 5 /1 4 (d) 1 4 /5 .

2.55. An axial load P is applied on a circular section of diameter D. If the same load is applied to a hollow circular section with inner diameter D /2, the ratio of stress in two cases would be(fl) 4 /3 (b) 1(c) 3 /4 (d) 1 /2 .

2.56. A square plate of thickness T is subjected to a tensile stress cr. in one direction and compressive stress


2.57.

2.58.

2.59.

2.60.

2 .61 .

(c) c v(l - v)t/2E(d) a x (1 - v) t /E.For a material with Poissons ratio p 0.3, the ratio of elastic modulus and modulus of rigidity E /G is (a) 0.65 (b) 2.6(ic) 1.3 (d) 1.4.The extension of a circu lar bar tapering uniformly from diameter d, at one end to diam eter at the other end, and subjected to an axial pull of P is given by

4PE ... 47i / d 2(a) 6/: 7i / dA (b) 1

(c)4PL

tcEd/d?

PE

4P /E

(c)

dx

a.td2 dx E

(b)

(d)

atd1

dxt aE rf,

2.62.

2.63.7i dxd2

The thermal stress in a circular bar tapering uniformly from diameter dx at one end to diam eter at the other end, is

, . a.t.Vd7 (a) ---------L2.64.

w here a = coefficient of linear expansiont = change in tempera ture, and E = modulus of elasticity of the bar materialThe maximum diameter of the hole fy /r rthat can be punched from a plate of maximum shear stress l /4 th of its maximum crushing stress of punch is equal to() t / 2 (b) f /4(c) 21 (d) At.where t = thickness of plateWhen a rectangular bar of lengthL, breadth b and thickness t is 2.66.stibjected to an axial pv of P, thenlinear strain is given by

(a) e =

(c) e =

b.t.Eb.tP.E

(b) e =

( d ) e =

b.t.EP

P.Eb.t

where e = linear strain, andE = mouduls of elasticity

When a rectangular bar of length L, breadth b and thickness t is subjected to pull of P, then volumetric strain is (a) e (1 - 2m) (b) e (2m - 1)(c) e (1 - 2 /m )(d ) e (2/m - 1). where e = Linear strain, and

1/m = Poissons ratio The relation betw een Young's modulus (E) and Bulk modulus (K) is given by

() K = ^ 2 K = j n E ^W mE W 3m -2

(c) K = ^ - Q ( d ) K = mR .m E 3(m - 2 )

When a cube is subjected to threem utually perp en d icu lar tensilestresses of equal intensity (P) thevolumetric strain is

(a) ^ ( 1 - 2 / m ) (b) ^ ( 1 - 2 / m )

(c) ^ ( 2 / m - l ) ( d ) ^ ( 2 / m - l ) .

The relation between modulus of elasticity (E) and modulus of rigidity (C) is given by

/ \ r - wE r _2(m + l)2(m + l ) (fc) mE

(c) C =2mE

(


2.67.

2.68.

2.69.

of the body inclined at an angle 0 to the normal of the section is {a) p cos 0 (b) p cos2 0(c) p sin 0 (d) p sin2 0. 2.70.When a body is subjected to a direct tensile stress (p) in one plane accom panied by a simple shear stress (q), the m inim um norm al stress is

J l ^ l

The strain energy stored in a body, when the load is gradually applied, is

()

(c)

pEV

p2 E 2V

(b)

(d)

pW_E

p2V 2E '

where p = Stress in the material of the body,

2.71.

(a) p / 2 +1 / 2^jp2 + Aq2

(b) p / 2 - 1 / 2^Jp2 +4 q2

(c) p / 2 + 1 / 2yjp2 - 4 q2

(d) p / 2 - \ / 2 ^ p 2 - k q 2 When a body is subjected to direct tensile stresses (pr and pn) in two mutually perpendicular directions, accom panied by a simple shear stress (q), then in M ohrs circle method, the circle radius is taken as

() +

(b)

2.73.

V = Volume of the body, and E = Modulus of elasticity of the material.The strain energy stored in a body due to shear stress, and

q 2C(a) ^ x V (b)

2C q.V

2C . .W ? v x V -

(C) _ L x V v ; 2Cwhere q = Shear stress,

C = Shear modulus andV = Volume of the body.

If the depth is kept constant for abeam of uniform strength, then itswidth will vary in proportional to

(fl) M (b) VM(c) M2 (d) M3.Where M = Bending moment For a beam as shown in Fig. 6, the deflection at C is

W

()

(b)

3/2

Fig. 6.WL3 48 EL

Wa2b2 3EIL

W a h2 ^ nV3EIL a 1

5WII ^ 384EI'where E = Young's modulus for

the beam material and I = Moment of inertia of

the beam section.For a beam as show n in Fig. 6, maximum deflection lies at


(a) L /3 from B (,b) L /3 from A

(c)

(d)

from B

L - b from A .

(a)

(c)

5 w l f 384El

3'ifL3

(&)iv\f 48EI

2.75.

2.76.

()

(c)

WL 3 El WL3

(b)

(d)

WL 8 El WL3

(a) Beam A (b) Beam B

Ffr. 7.

The ratio of maximum deflection of beam A to beam B is (a) 8 /7 (b) 1 6 /7(c) 3 2 /7 (d) 4 5 /7 .

2.78. Two cantiliver beams are shown in Fig. 8. The ratio of m axim um deflection of beam A to the beam B

2.74. The sim ply supported beam of length L loaded with a uniformly distributed load of w per unit length. The maximum deflection will be

is WTotal load W

(b) Beam BFig. 8.

(b) 6 /5 (d) 6 /1 5 .

2.79.48EI

A simply supported beam A of length / carries a central point load W. Another beam "B is loaded with a uniformly distributed load such that the total load on the beam is W. The ratio of m axim um deflections between beams A and B is(a) 5 /8 (b) 8 /5(c) 5 /4 (d) 4 /5 .The m axim um deflection of a cantilever beam of length I with a point load W at the free end is

(a) Beam A

(a) 5 /6 (c) 1 5 /6Two fixed beams are shown in Fig. 9. The ratio of maximum deflection of beam A to maximum deflection of beam B is

WTotal load WF5 ^ X5

2 ....---------/ --------- >


of

mimiB

!g-onon

(E)l as

;A )thvn

The deflection of beam "B with compared beam A (a) one fourth (b) one-half (c) double (d ) eight times.

1 52. A pressure vessel is said to be thin walled when the ratio of internal diameter and wall thickness of the vessel is(a) 5 (>) 10(c) 15 (d) more than 20.

I. S3. The C.G. of a solid cone of height h lies on, its vertical axis at the height of(r?) h / 8 (b) h / 4(c) 2 /3 h (d) 5/8/7.

2.34. M om ent of inertia is a concept applicable in case of(a) a rotating body(b) body moving in a straight line(c) body at test(d) both for (a) and (b) above.

2.85. If IG is the moment of inertia of a section about an axis passing through its centre of gravity, G and y is the maximum distance of its extrem e end from G, then, the section modulus denoted by Z is equal to(a) IG.J/ (b) IG - y

(c) lG.y2 (d) k .y

2.86. The moment of inertia of a thin ringof m ass M about an axis perpendicular to plane of the ring is (r = distance of axis from plane)(a) Mr (b) Mr2(c) Mr3 (d) 1 /3 Mr3.

2.87. Moment of the inertia of a right circular cylinder of radius p and mass m or given by(a) 77?R2 (b) 1 /2 77/R2(c) ;7zR2/ 3 (d) mR2/4 .

2 .88 . The polar modulus for a solid shaft of diameter (d) is

(0>

w f /2.89.

(a) 7t/4 d2

(c) d3 K 32Two beams A and B' carrying a central point load W are shown in Fig. 11.

w W4 $

5


2.93.

2.94.

2.95.

2.96.

2 .9 7 .

T / s C0 In the torsion equation = rr- =

ip I\ I

the term Ip/R is called(a) shear modulus(b) section modulus(c) polar modulus(d) none of the above.The torque transmitted by a hollow shaft of outer diam eter (D) and inner diameter (d) is

() T * / .

(b)

(0 Z ' A

U) x , ;32

DD

D3- d D

D4 - d D

1D 4D

()

(c)

ttNT 75

271 NT

h.p. (b)

h.p. (d)

7 t N T

45002ttNT

h.p.

h.p.

(c)27iTco

-watts(rf)27iTco

watts.

2.98.

A shaft revolving at N r.p .m . transmits torque (T) is kg m. The power developed is

75 r ' 4500A shaft revolving at ra d /s e c transmits torque (T) in Nm. The power developed is (n) T.co watts (b) 2n Too watts

(a) 1 /1 6 (b) 1 /8(c) 1 /4 (d) 1 5 /1 6The strain energy stored in a hollow circular shaft of outer diameter (D) and inner diameter (d) subjected to

x volume of shaft

shear stress ( f j is

f? f V2 - d 2\() 2G K D J

fs ' D2 + d2}(b) 2G I D J

fs f 2 " ^ 1(c) 4G I D Jf:f ( D 2 + d2\

(d) 4G { D J

x volume of shaft

x volume of shaft

x volume of shaft.

2.99.

75 v" / 4500Two shaft A and B are made of same material. The shaft A is solid and has diameter D. The shaft B is hollow with outer diameter D and inner diameter D /2 . The strength ofhollow shaft in torsion is......as thatof solid shaft.

The load required to produce a unit deflection in a spring is called(a) flexural rigidity(b) torsional rigidity(c) spring stiffness(d) Young's modulus.

2.100. The closely coiled helical springs A and B are equal in all respect but the number of turns of spring A is half that of spring B\ The ratio of deflection in spring A to spring B is(a) 1 /8 (b) 1 /4(c) 1 /2 (d) 2.

2.101. Two closely-coiled helical springs A and B are equal in all respect but the number of turns of spring A is double that of =>pring B\ Thestiffness of spring A will b e .... thatof spring B(a) one-sixteenth(b) one-eight(c) one-forth(d) one-half.

2.102. A closely-coiled helical springs is cut into two halves. The stiffness of the resulting spring will be


(a) same (b) double(c) half (d ) one-fourth.

2.103. A thin cylindrical shell of diameter(d), length (/) and thickness (t) is subjected to an internal pressure (p). The hoop stress in the shell is(a) p d / t (b) p d / 2 t(c) pd/At (d) pd /6 t .

2.104. A thin cylindrical shell of diameter(d), length (I) and thickness ( f) is subjected on internal pressure (p). The longitudinal stress in the shell is(a) p d l /2 t (b) pdl /At(c) pdl/ 6t (d) none of these.

2.105. In a thin cylindrical shell, the ratio of longitudinal stress to the hoop stress is{a) 1 /2 (b) 3 /4(c) 1 (d) 15.

2.106. The hoop stress in a thin cylindrical shell is(a) longitudinal stress(b) compressive stress(c) radial stress(d) circumferential tensile stress.

2.107. A thin cylindrical shell of diameter(d), length (I) and thickness (f), is subjected to an internal pressure (p). The circumferential or loop strain is

&('->>jpd_(}__ JO yd f i i 2fEv2 m ) ^ I f E U m ,

where 1 /m = Poisson's ratio2.108. When a thin cylindrical shell is

subjected to an internal pressure, the volumetric strain is(a) 2ey - e2 {b) 2e1 + e2(c) 2e2 - e1 (d ) 2e2 +where = hoop strain, and

(c)

2.109. A thin cylindrical shell of diameter(d), length (/) and thickness (t) is subjected to an internal pressure (p). The ratio of longitudinal strain to hoop strain is

m - 2 ... 2m - 1()

(c)

2m - 1 m - 2

(b)

(d)

m - 2 2m +1m

2 .110 .

(0)

(c)v Atn (d)

e2 = longitudinal strain.

2m +1The hoop stress in a riveted cylindrical shell of diameter (d), thickness (t) and subjected to an internal pressure (p) is

pd tn

pdt ~2n'

where n = no. of rivets.2.111. A thin spherical shell of diameter (d)

and thickness (t) is subjected to an internal pressure (p). The volumetric strain is

(fl) i l (1 1/m)(fc) ^ (1 1/m )

(C) ^ ( 1 - 1 / m ) .2.112. The assum ption made in Euler's

column theory is that(a) the failure of column occurs due

to buckling alone(b) the colum n m aterial obeys

Hooke's law(c) the shortening of column due to

direct compression is neglected(d) all of the above.

2.113. According to Euler's column theory, the crippling load for a column oflength (/) fixed at both ends i s .....the crippling load for a sim ilar column hinged at both ends.(a) equal to (b) two times(c) four times (d) eight times.


2.114. According to Euler's column theory,the crippling load of a column is given by P = 7t2E I /C /2. In this equation, the value of C for a column with both ends hinged, is(a) 1 /4 (b) 1 /2(c) 1 (d) 2.

2.115. A vertical column has two moment of inertia (i.e., Ixx and I ). The column will tend to buckle in the direction of the(a) axis of load(b) perpendicular to the axis of load(c) maximum moment of inertia(d) minimum moment of inertia.

2.116. The columns whose slenderness ratio is less than 80, are known as(a) stress columns(b) long columns(c) weak columns(d) medium columns.

2.117. In a stress-strain diagram for mild steel as shown in Fig. 12, the point A represents

Fig. 12.(a) elastic limit(b) upper yield point(c) lower yield point(d) breaking point.

2.118. In Fig. 12, the point C represents(a) elastic limit(b) upper yield limit(c) lower yield limit(d) breaking point.

2.119. In Fig. 12, stress is proportional to strain, for the portion(a) from O to A (b) from A to C(c) from A to D(rf)from C to D.

2.120. A tensile test in performed on a round bar. After fracture it has been found that the diameter remains approximately same at fracture. The material under test was(a) mild test (b) cast iron(c) glass (d) copper.

2.121. If percentage reduction in area of a certain specimen made of material A under tensile test is 60% and the percentage reduction in area of a specimen with same dimensions made of material B is 40%, then(a) the material A is more ductile

than material B(b) the material B is more ductile

than material A(c) the ductility of material A and

B is equal(d) the m aterial A is brittle and

material B is ductile.2.122. In a stress-strain diagram as shown

in Fig. 13, the curve A represents

Fig. 13.(a) mild steel (b) soft brass(c) glass (d) cold rolled steel

2.123. In Fig. 13 ...... represents glass.(a) curve A (b) curve B(c) curve C (d) curve D.

Strength of Materials 2.71

>nal to

3 C 3 D. i on a is been mains re. The

ea of a laterial ind the ;a of a nsions , then luctile

ductile

A and

le and

shown;sents

d steel, iss.

2.124. The angle of obliquity (J>, the normal stress ct)( and the tangential shear stress x0 are related to an oblique plane of on element. The resultant stress o r is expressed by

() o,- c l + T o (b) CTr = >/ ? + x [

:.i25 .(c) c r - o + xe(d) cr, = J a t + Tl A complex stress is (fl) shear stress(b) normal stress(c) com bination of norm al and

shear stress (d) none of the above.

2.126. The angle between a principal planeand the plane of maximum shear is (fl) 45 (b) 90(c) 135 (d) 180.

2.127. The sum of norm al stress in a compound stress system is(a) constant(b) variable linearly(c) variable parabolically(d) none of the above.

2.128. Extremeties of a vertical diameter on a Mohr's circle represents(a) Principal stress(b) Maximum shear stresses(c) Maximum normal stress (id) None of the above.

2.129. If the principal stress in a stressedbody are 100 N /m m 2 and - 50 N / mm2, the maximum shear will be (fl) 150 (b) 50(c) 75 (d) 25.

2.130. If the major and minor principal stresses in a stressed body are 100 N /m m 2 and 50 N /m m 2 the Mohrs circle radius will be() - 50 - (b) 25(c) 75 (d) - 25.

2.131. Net force acting across a cross- section of bent-beam is

(fl) tensile (b) compressive(c) zero (d) shear.

2.132. A section of a beam is supposed to be under pure bending if it is subjected(fl) a constant B.M. and a constant

S.F.(b) constant B.M. and zero S.F.(c) constant S.F. and zero B.M.(d) none of the above.

2.133. Two beams having equal areas of cross-section, but one being circular and other square in section when subjected to B.M. are(fl) equally strong(b) square section is move

economical(c) both sections are equally

economical(d) circu lar section is m ove

economical.2.134. In a flitched-beam of steel and

w ood, stressed at all com m on surface will be(fl)(b) CT(0 a . > a u (d) none of the above.

2.135. The diameter of the core (kemal) of a circular section and eccentric loading is

CTs ='10 > as

, , d 4

(c) (d)d2 '

2.136. For no tensile stress under bending and axial loading middle-third rule applies to section(fl) circular (b) rectangular(c) elliptical (d) straight.

2.137. The shear force on a deflected beam is given by


(a) V = EIdydx

(b) v = e i 4 4

(c) V = E I 0

dx24.

(d) V = E I - i .dx4

2.138. Maximum deflection in a simply supported beam with a U.D.L. iv over the entire span is given by

(fl)

(c)

zvlf 48EI w L3 3 El

(&)

(d)

5384 El

h;L3

8 El2.139. Maximum deflection in a cantilever

beam with U.D.L. over the entire span is given by

()

(c)

wL 48 El

wL3 3 El

(b)

(d)

5 ivL 348 El

zoL3 8 El

()

(c)

3WL Inbt2 E

6WL3

(*0

(d)

3WL 8nbt3 E

WL3 6nbt2 E '

(c)

2 nbt2 3WL2 nbt2 ^ 2 nbt2 '

2.143. In case of a belt drive torque is given by

2 nbt WL

() (T1 - T 2 )

(b) (T i-T 2) x radius

(c) (T1 -T 2) x diameter

(d) (Ti - T 2) 1 / 3 diameter.2.144. Shear stress produced will be

(a) maximum at the centre(b) minimum at the centre(c) maximum at the circumference(d) minimum at the circumference.

2.145. Angle of twist on a shaft under pure torque is given by

TL TL() 1 G

(c)T x G Ip x L


2.150. Shear stress in a closed coiled spring under axial load is given by

(fl)

(c)

8WD nd3

8WD

(b)

(d)

8WRnd3

8WR

2.151.

(fl)

(c)

16WD n Gd4

64 WD 3n

(b)

(d)

64 WD nGd4

32 WD 3n

2.152.

(fl) W x 5

W(c)

5

(*0 W

(rf) W x 81/2.

2.153. In a close-coiled spring subjected to axial couple, the rotation of free end is

(fl)

(c)

2 ML El

4 ML

(b)

(d)

3 ML El

ML

2.154.El El

Equivalent spring constant for springs in series is given by

h + fc, V

K ~^2

(b)

(d)

kx + k2

1^^ 2

2 .155 .(C) kxk2 kx - k} 'Torque in a flat spiral-spring is given

Tmax^ /m 4 M 2

2.156. ,Strain energy in a flat spiral spring given by

7iR"1 nd3Deflection 8 in a closed coiled helical spring under axial load is given by

(fl)

(b)

(c)

(d)

2E

max

12E

T2l max

24 E

x2m ax6E

x volume

x volume

x volume

x volvune.

Gd4 v~' Gd4where d = Dia. of spring wire

n - no. of turns of the spring G = Modulus of rigidity D = Mean dia. of helical spring

Stiffness of a spring is determined from

2.157. In the Rankine-Gordon formula the value of Rankines constant or for steel is

1 ... 1()

(c)

50001

(b)

(d)

75001

1600 4500 2.158. Shrinking of a jacket on a cylinder

is done to(a) increase the hoop-stress(b) increase the radial stress(c) decrease the hoop-stress(d) decrease the radial stress.

2.159. Resilience is given by the relation

(fl) 2E.2

wfi

2.160. Resilience in a two dimensional stress system is given by (^ = Poisson's ratio)

(a) + ct^ + 2|ict2ct2]

(b) ~ [ CTi + cr2 - 2|kj2cj2]

(c) - ^ [ o l + G22 + 2 [ ia l c 22]


2.161. A m aterial which undergoes no deformation till its yield point is reached and then it flows at a constant stress is known as(a) Elasto-plastic (b) Plasto-electric(c) Rigid-plastic (d ) Rigid-elastic.

2.162. The shape of the kern area for a rectangular section is(a) circle (b) square(c) rectangle (d) parallelogram.

2.163. The Youngs modulus of elasticityis determ ined for mild steel in tension and compression, the two values will have a ratio (Ef/E (.) of (a) 1 (b) 0.5(c) 1.2 (d) 2.

2.164. In a case of a rectangular beam of cross-section a x b, the core is(a) square of side b / 2(b) square of side a / 2(ic) rectangle of sides a / 2 and b /2(d) Rhombus of diagonal b / 2 and

b /3 .2.165. Poisson's ratio for cast iron is

(a) 0 .27 (b) 0.31(c) 0.33 (d) 0.36.

2.166. The numerical values of Youngs modulus of elasticity in descending order for wood, lead, glass, steel and phosphor bronze are given by(a) steel, phosphor-bronze, glass,

lead and wood(b) steel, glass, phosphor-bronze,

lead, wood(c) steel, w ood, lead, phosphor-

bronze, glass(d) steel, lead, w ood, phosphor-

bronze, glass.2.167. The average values of modulus of

rigidity for alum inium , brass, copper, nickel and steel in descending order are given by(a) alum inium , brass, copper,

nickel, steel

(b) alum inium , copper, nickel, brass, steels

(c) aluminium, nickel, steel, brass, copper

(d) brass, copper, alum inium , nickel, steel.

2 .1 6 8 . The num erical value of Youngs m odulus of elasticity in the ascending order for glass, aluminium, copper, wrought iron and tungsten are given by(a) tungsten, wrought iron, copper,

aluminium glass(b) w rought iron, copper,

aluminium, glass, tungsten(c) copper, alum inium , glass,

timgsten, wrought iron(d) glass, alum inium , copper,

wrought iron, tungsten.2 .1 69 . The numerical values of Young's

modulus of elasticity in ascending order for aluminium bronze, brass, inconel and Muntz metal are given in(a) muntz, metal,brass, aluminium

bronze, inconel (.b) m untz m etal, alum inium ,

bronze, brass inconel(c) inconel, m untz metal,

aluminium, bronze, brass(d) alum inium , bronze, muntz

metal, inconel, brass.2 .1 70 . A m aterial capable of absorbing

large amount of energy is known as(a) Ductile (b) shock proof(c) hard (rf) tough.

2 .1 71 . The slenderness ratio of vertical column square cross-section of 25 cm sides and 600 cm effective length is(a) 100 (b) 240(c) 500 (d) 900.

2 .1 72 . In Mohr's circle, the distance of the centre of circle from i/-axis is


() (Px ~n -t- n

(c) 2 ' 7 2 2.173. The failure of a m aterial under

varying load, after number of cycles of such load, is known as(a) Ductile failure(b) Brittle failure(c) Impact failure (id) Fatigue failure.

I 174. The ratio of Bulk modulus to shear modulus for Poisson's ratio of 0.25 will be(a) 3 /2 (b) 5 /6(c) 1 (d) 6 /3 .

I 175. Clad metals are(a) non-ferrous materials

(c) two or more dissimilar materials \ointed together by welding

(d) Two or m ore dissim ilar materials jointed together under vary high hydraulic pressure.

2.176. When a strip m ade of iron and W er is heated

(a) it bends(b) it gets twisted(c) iron bends on conex side(d) iron bends on cancave side.

2.177. Two rods A and B are subjected to

2.178 .

equal load P. Rod A is tapering w ith bigger diam eter D at the support and small end diameter as D /2 Rod B is uniform cross-section w ith diam eter D. The ratio of elongation of rod A to that of B would() 4 (b) 2(c) 1 (


T13

+25

i

.5 ^25

2.5

- 5 ^ 134-

538

Fig. 14.(fl) A(b) B(c) C(d ) all will have equal energy stored.

2.185. Two shafts of the same material are subjected to the same torque. If the first shaft is of solid circular section and the second shaft is of hollow section whose internal diameter is 2 /3 of the outside diameter, the ratio of weights of hollow shaft to solid shaft would be(a) less than 0.5(b) between 0.5 to 0.99(c) 1(id) 1 to 1.5.

2.186. The longitudinal strain for a specimen is 0.01 and it is found to undergo 1 mm change in its thickness. The thickness of the specimen will be(fl) 10 mm (b) 100 mm(c) 400 mm (d) 1000 mm.

2.187. The ratio of central deflection in abeam freely supported at both ends to that when the beam is fixed at both ends and subjected to a central load W in both the cases would be (fl) 1 (b) 1 /2(c) 1 /4 (d) 4.

2.188. A vertical load P = 2100 kg is supported by two inclined steel wires AC and BC as shown in Fig. 15. If the allowable working stress in tension is 700 kg/cm 2 and angle

Fig. 15.

A is 30, the cross-sectional area of each wire should be less than (fl) 1 sq cm (b) 2 sq cm(c) 2.5 sq cm (d) 3.05 sq cm.

2 .1 89 . A short hollow cast iron cylinder with a wall thickness of 1 cm is to carry a com pressive load of 10 tonnes. If the w ork stress in com pression is 800 k g /cm 2, the outside diam eter of the cylinder should not be less than(fl) 0.5 cm (b) 1.0 cm(c) 2.5 cm (d) 5 cm.

2 .1 9 0 . Castellated beams are used for (fl) light construction(b) resisting bending moment onlv(c) loads not passing through shear

centre(d) section subjected to alternate

compressive and shear stres2 .1 91 . At a certain point in a structur

member, the value of = 45 mm2, a }/ = 75 N /m m 2 and x = 45 N mm2. The principle stresses will (fl) 120 N /m m 2 and 30 N /m m 2(b) 120 N /m m 2 and - 30 N /m m ;(c) 90 N /m m 2 and 60 N /m m 2(d) 90 N /m m 2 and - 60 N /m m -.

2 .1 9 2 . Eccentrically loaded columns a generally subjected to (fl) axial compression and tensi(b) bending stress and axi

compression


(c) shear stress and axial compression

(d ) bending stress, shear stress and axial compression.

2.193. For a material having E = 11000 t / cm 2 and C = 430 t / cm 2, the Poisson's ratio will be(fl) 4 3 /5 5 (b) 1 2 /4 3(c) 3 1 /4 3 (d) 1 2 /5 5 .

2.194. Stages in a tensile test areI. yield point

II. elastic limitIII. Limit of proportionalityIV. Maximum load pointV. Breaking pointThe correct order of these stages in a tensile test on a ductile material is (fl) I, II, III, IV, V(b) V, IV, III, II, I(c) III, II, I, IV, V (d) III, I, II, V, IV.

1 195. A 50 x 25 mm copper flat is brazed to another 50 x 50 mm steel flat as show n in Fig. 16. When the com bination is heated through 100C.

25

50

Copper

Steel

Fig. 16.copper will be under tensile strain and steel will be under compressive strain steel will be under tensile strain and copper will be under compressive strain steel will be under compressive strain

(d) both will be under compressive strain.

1.196. An underground pipeline is laid in spring at 35C. If the pipeline is unable to contract during w ater

()

(b)

(c)

when temperature drops to 5C, the pipe will be under (fl) hoop stress(b) compressive stress(c) hoop and compressive stress(d) tensile stress.

2.197. Shown in Fig. 72 given below is an element of an elastic body, which is subjected to pour shearing stresses x . The absolute value of the magnitude of the principle stresses

(fl) zero

(c) '

Fig. 17.

(b)

(d)

xy

xy \ x y

2.198. Stress strain curve for the fibre glass can be expected to be of the pattern shown in Fig. 18

Fig. 18.


{a) Figure A (b) Figure B(c) Figure C (d ) Figure D.

2.199. Two area under stress strain curve, shown in Fig. 19, represents

(a) work done

(b) ductility

(c) strain energy

(d) residual stresses

2.200. For the diagram shown in Fig. 20, the m axim um shearing stress in MPa is

40 Mpa *

60 Mpa

40 Mpa

60 Mpa

Fig. 20.

{a) 80 (b) 70(c) 60 (d) 50

2.201. Brass could not be used to reinforce concrete because(a) its density is too high(b) its density is too low(c) it is too expensive(d) it is coefficient of therm al

expansion is not right2.202. For the diagram shown in Fig. 21,

Fig. 21.

the m axim um shearing stress MPa, will be (fl) 80 (b) 60(c) 50 {d) 40.

2 .2 03 . A certain point in a struc member the value of

a x = 45 N /m m 2 a = 75 N /m m 2

and t = 45 N /m m 2 The principal stresses will be(a) 120 N /m m 2 and 30 N /m rrr(b) 120 N /m m 2 and - 30 N /i(c) 90 N /m m 2 and 60 N/mm*(d) 90 N /m m 2 and - 60 N /m nr

2. 2 0 4 . The moment of inertia of an will be least with respect to(a) central axis(b) horizontal axis(c) vertical axis(d) moment of area does not d

on axis.2 .2 0 5 . The value of Young's modulus

elastic for structure steel is ta(a) 2.04 to 2.18 x 106 kg/cm -(b) 5.00 to 5.98 x 107 kg/cm -(c) 8.0 to 9.0 x 108 kg/cm 2(d) 10.0 to 12.0 x 1010 kg/cm ; .

2 .2 06 . A solid cube is subjected to normal forces on all its faces, volumetric strain will be x-tir linear strain in any of the three when(a) x = 1 (b) x = 2(c) x = 3 (d) x = 4.

2.207 . A steel rod of 2 cm diameter metres long is subjected to an pull of 3000 kg. If E = 2.1 x 10*. elongation of the rod will be (a) 2.275 mm (b) 0.2275 mm(c) 0.2275 mm (d) 2.02275 m a

2 .2 08 . The ratio of the tensile s developed in the wall of a bo" the circumferential direction t:


tensile stress in the axial direction,is(a) 4 (b) 3(c) 2 (d) 1 .

2.209. The maximum compressive stress at the top of a beam is 1600 kg/cm 2 and the corresponding tensile stress at its bottom is 400 kg/cm 2. If the depth of the beam is 10 cm, the neutral axis from the top, is(a) 2 cm (b) 4 cm(c) 6 cm (d) 8 cm.

2.210. If the width of a simply supported beam carrying as isolated load at its centre is doubled, the deflection of the beam at the centre is changed by(a) 2 times (b) 4 times(c) 8 times (d) 1 /2 times.

2.211. If the width of a simply supported beam carrying an isolated load at its centre is doubled, the deflection of the be'am at the centre is changed by(n) 1 /2 (b) 1 /8(c) 2 (d) 8.

2.212. The length of a column having a uniform circular cross-section of 7.5 cm diameter and whose ends are hinged, is 5 m. If the value of E for the material is 2100 tonnes/cm 2, the permissible m axim um crippling load will be(n) 1.288 tonnes (b) 12.88(c) 128.8 tonnes (d) 288.0.

2.213. The slenderness ratio of a verticalcolumn of a square cross-section of 2.5 cm sides and 300 cm length, is(a) 200 (b) 240(c) 360 (d) 416.

2.214. A short masonry pillar is 60 cm x 60 cm ilf cross-section, the core of the pillar is a square whose side is

(a) 17.32 cm (b) 14.14 cm(c) 20.00 cm (d) 22.36 cm.

2 .2 1 5 . A member which is subjected to reversible tensile or compressive stress may fail at a stress lower than the ultimate stress of the material. This property of metal, is called(a) plasticity of the metal(b) elasticity of the metal(c) fatigue of the metal(d) workability of the metal.

2 .2 16 . The section modulus of rectangular light beam 25 meters long is 12.500 cm3. The beam is simple supported at its ends and carries a longitudinal axial tensile load of 10 tonnes is addition to a point load of 4 tonnes at the centre. The maximum stress in the bottom fibre at the mid span section, is(a) 13.33 k g/cm 2 tensile(b) 13.33 kg/cm 2 compressive(c) 26.67 kg/cm 2 tensile(d) 26.67 kg/cm 2 compressive.

2 .2 1 7 . The shear stress at any section of a shaft is maximum(a) at the centre of the section(b) at a distance h / 2 from the centre(c) at the top of the surface(d) at a distance 3 / 4 r from the

centre.2 .2 18 . The following assumption is not true

in the theory of pure torsion :(a) the tw ist along the shaft is

uniform(b) the shaft is of uniform circular

section throughout(c) cross-section of the shaft, which

is plane before twist remains plane after twist

(d) all radii get twisted due to torsion.2 .2 19 . The maximum twisting moment a

shaft can resist, is the product of the permissible shear stress and


(a) moment of inertia(b) polar moment of inertia(c) polar modulus(d) modulus of rigidly.

2. 220 . If a rectangular beam measuring 10 x 18 x 400 cm carries a uniformly distributed load such that the bending stress developed is 100 kg/ cm2. The intensity of the load per metre length, is(fl) 240 kg (b) 250 kg(c) 260 kg (d) 270 kg.

2.221 . The num ber of points of contraflexure in a simple supported beam carrying uniformly distributed load, is(fl) 1 (b) 2(c) 3 (d) 0.

2.222 . For a channel section, the shear centre lies at a distance of

(b) ^(")

(c)

bdt_21

t4/

(d)

31

dbh51

2.2 23 . A triangular section having base b, height h, is placed with its base horizontal. If the shear stress at a depth 1/ from top is q, the maximum shear stress is

. 3S /1X 4S(n> bh bh

I I'2 .2 2 4 . In a tension test, the yield stress is

300 kg/cm 2, in the octahedral shear stress at the point is

() 100^2 kg/cm 2

(f>) 150V2 kg/cm 2

(c) 200/2" kg/cm 2

(d) 25042 kg/cm 2

2.225. A shaft 9 m long is subjected to a torque 30 t-m at a point 3 m distance from either end. The reactive torque at the nearer end will be (fl) 5 tonnes metre(b) 10 tonnes metre(c) 15 tonnes metre(d) 20 tonnes metre.

2.226. In a universal testing machine during the testing of a specimen of original cross-sectional area 1 cm-, the m axim um load applied was 7,500 tonnes and neck area 0.6 cm. The ultimate tensile strength the specimen is (fl) 12.5 tonnes/cm 2(b) 10.0 tonnes/cm 2(c) 7.5 tonnes/cm 2 (1d) 3.5 tonnes/cm 2.

2.227. In a compression test, the frac in cast iron specimen would oc along(a) an oblique plan(b) along the axis of load(c) a light angles to the specim

axis(d) fracture will not occur in c

iron.2.228. A uniform beam of effective len

L, fixed at one end and load uniform ly will have m axim u deflection at(fl) 7 /8 L from fixed end(b) 3 /8 L from free end(c) 5 /8 L from free end(d) L /V 5 from free end.

2.229. The area around tVve centre gravity of a cross-section with" w hich any load applied wi produce stress of only one si throughout the enter cross-secti is known as(fl) kern (b) neutral zone(c) symmetrical(rf) balance zone.

Strength of Materials 2.81

cted to a (m distance

vetorque

machinecsxcvexv oV

a \ crw2 , \\ed w a s

a 0.6 sq. ength of

fracture Id occur

1 specimen

ir in cast

ive length j id loaded laximui

1.230. Two bars of different materials are of the same size and are subjected to same tensile forces. If the bars have unit elongation is the ratio of7.3, then the ratio of modulii of elasticity of the two material is (a) 7.3 (b) 3.7(c) 64.9 (d) 9.64.

1231 . Modular ratio of the two materials Ss. x-aXivo

(a) linear stress to lateral strain(b) linear stress to linear strain(c) shear stress to shear strain(d) their modulus of elasticities.

2.232. A bar length L meters extends by 2mm under a tensile force P kg. The strain produced in the bar is (a) 2 / L lb) 0 .2 /L(c\ Q.Q02/L (d\ Q.QQQ2/L.

2.99. I ' .r .

113.1120.

; e n t r e o f 1 n w it h in 1

. i e d w i l l !2LI34.

o n e s ig n 11 - - - se c t io n 1

1141. ZL14-*.

-ai z o n e ice /one.

1 : :

b) 2.2. (c) 2.3. (c) 2.4. (b) 2.5. (c) 2.6. () 2.7. (c)) 2.9. (d) 2.10 . () 2 r \ . (a) 2.12 . (b) 2.13 . (b) 2.14 . (d)d) 2.16 . (c) 2. 17 . (c) 2.18. (b) 2.19 . (a) 2.20 . (d) 2.21 . (d)b) 2.23 . (d) 2.24 . (c) 2.25. (b) 2.26 . (c) 2.2 7 . () 2.28 . (b)d) 2.30 . (c) 2. 31 . (c) 2.32. (d) 2.33 . (c) 2.34 . (b) 2.35 . (fl)b) 2.3 7 . (a) 2. 38 . () 2.39. (d) 2. 40 . (c) 2. 41 . (d) 2.42 . ()b) 2.44 . (c) 2. 45 . (b) 2.46. (n) 2. 47 . (c) 2. 48 . (b) 2.49 . (d)b) 2.51 . (d) 2. 52 . (c) 2.53. (ic) 2.54 . (a) 2. 55 . (c) 2.56 . (a)b) 2.58 . (c) 2.59 . () 2.60 . {d) 2.61 . () 2.62 . (c) 2.63 . (d)(i) 2.65 . (a) 2. 66 . (b) 2.67 . (b) 2.68 . (c) 2.69 . (d) 2.70 . (c)) 2.72 . (b) 2. 73 . (C) 2.74 . (a) 2. 75 . (b) 2. 76 . () 2.77 . (d)a) 2. 79 . (a) 2.80 . (c) 2.81 . (d) 2. 82 . (d) 2. 83 . (b) 2.84 . (a)d) 2. 86 . (b) 2 .87 . (b) 2.88 . (b) 2.89 . (b) 2. 90 . (b) 2.91 . (c)b) 2.93 . (c) 2 .94 . (c) 2.95 . (d) 2.96 . () 2.97 . (d) 2.98. id)c) 2 .1 00 . (c) 2 .1 01 . (d) 2.1 02 . (b) 2 .1 0 3 . (b) 2 .1 0 4 . (d) 2 .1 05 . ()d) 2 .1 07 . (a) 2 .1 08 . (b) 2.1 09 . (a) 2 .1 1 0 . (b) 2 .1 1 1 . (c) 2 .1 12 . (d)

c) 2 .1 14 . (c) 2 .1 15 . (d) 2.1 16 . (a) 2 .1 1 7 . () 2 .1 1 8 . (c) 2 .1 19 . ()b) 2 .1 21 . (a) 2 .1 22 . (b) 2 .1 23 . (c) 2 .1 24 . (b) 2 .1 2 5 . (c) 2.1 26 . ()b) 2 .1 28 . (b) 2 .1 2 9 . (c) 2. 130 . (c) 2 .1 31 . (c) 2 .1 3 2 . (b) 2.1 33 . (d)

c) 2 .1 35 . (a) 2 .1 36 . (b) 2 .1 37 . (c) 2 .1 3 8 . (b) 2 .1 39 . (d) 2.1 40 . (d)

b) 2 .1 42 . (c) 2 .1 43 . (b) 2. 144 . (c) 2 .1 45 . () 2 .1 46 . (b) 2 .1 47 . (b)c) 2 .1 49 . (c) 2 .1 50 . () 2. 151 . (b) 2 .1 52 . (0 2 .1 5 3 . (d) 2 .1 54 . (b)) 2 .1 56 . (c) 2 .1 57 . (b) 2. 158 . (c) 2 .1 5 9 . (b) 2 .1 6 0 . (b) 2 .1 61 . (c)d ) * 2 .1 63 . (a) 2 .1 64 . (d) 2 .1 65 . (a ) 2 .1 6 6 . () 2 .1 6 7 . () 2.168 . (rf)

%2.82 Civil Engineering (Objective Type)

2.169 . (fl) 2 . 17 0 . (d) 2 .1 7 1 . (b) 2 .1 72 . (c) 2. 1 7 3 . (d) 2 .1 7 4 . (c) 2.1 75 . til2 .176 . (d) 2. 1 7 7 . (b) 2. 17 8 . (d) 2 .1 79 . (c) 2. 1 8 0 . (d) 2 .1 8 1 . (c) 2 .1 82 . (#1

2.183 . (c) 2 .1 84 . (c) 2 .1 85 . (b) 2 .1 8 6 . (b) 2 .1 8 7 . (d) 2 .1 8 8 . {d) 2 .1 89 . (J2.190 . () 2 .1 9 1 . (d) 2 .1 9 2 . (b) 2.193 . (b) 2 .1 9 4 . (c) 2 .1 9 5 . (b) 2.196 . ( 42 .197 . (d) 2 .1 9 8 . (fl) 2 .1 9 9 . (c) 2 .2 00 . (d) 2 .2 0 1 . (d) 2 .2 0 2 . (c) 2.203 . tij2 .204 . (fl) 2 .2 0 5 . (fl) 2 .2 06 . (c) 2 . 2 0 7 (b) 2 .2 0 8 . (c) 2 .2 0 9 . (rf) 2 .210 . (rj

2.211. (fl) 2 .2 1 2 . (b) 2 .2 13 . (d) 2.214 . (b) 2 .2 1 5 . (c) 2 .2 1 6 . (c) 2 .2 17 . ( 4

2 .218 . (d) 2 .2 1 9 . (?) 2 .2 2 0 . (b) 2.221 . (d) 2.222. (c) 2 .2 2 3 . (a) 2.224. (4

2.225. (d) 2 .2 2 6 . (c) 2 .2 2 7 . () 2 .2 28 . (b) 2.229. (a ) 2 .2 3 0 . (b) 2.2 31 . ( 42.232. (c)

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