Imp Questions x Class

8/10/2019 Imp Questions x Class

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SOME TIPS FOR STUDENTS ON EXAMINATION

1. Read question Paper very carefully.

2. Attempt those questions rst where you are sure of answers.

3. Draw diagrams wherever possible.

4. Diagram should be neatly drawn and well labelled.

5. Diagram should be self-explanatory.

6. Alongwith the diagram; write two or three important points.

7. Write answers point wise.

8. Do not write long sentences or long paragraphs.

9. Try your best not to leave any question unanswered.

10. underline mportant words, terms, and points with pencile or green/yellow pen/

highlighter.

11. Avoid using red pen.

12. Time yourself - you should complete your paper within the time limit.

13. Try to keep 10 minutes in the end for revision.

14. Do not leave blank papers between two answers in answer sheet.

15. Use smooth pen, pencil, and rubber for exam.

16. Do not waste paper - think for the environment


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FORMATIVE ASSESSMENT

I. Class Response Assessment Worksheet

1. Which two circuit components are connected in parallel in the circuit diagram ?

a. Rheostat and voltmeterb. Voltmeter and resistorc. Voltmeter and ammeterd. Ammeter and resistor

2. In a voltmeter there are 20 divisions between the 0 mark and 0.5 v mark. The least countof voltmeter is-

a. 0.20v b. 0.025v c. 0.050 v d. 0.250 v3. The current owing through a resistor connected in a electrical circuit and potential

difference developed across its ends are shown

The value of resistance of the resistor in ohms isa. 25 b. 20 c. 15 d. 10

4. Which of the, following graphs shows a relationship between current and voltage as perohms law?

a. b. c. d.

5. Which of the following is the correct relation between V, I & R.a. b. c. d. R = VI

6. The unit of resistance isa. Ohm b. Volt c. coulomb d. Ampere

7. The instrument used for current measurement is-

a. Galvanometer b. Voltmeter c. frequency meter d. Ammeter8. The symbol indicates

a. Key b. Resistor c. Bulb d. Rheostat9. Symbol commonly used in circuit diagrams for wires crossing without joining is-

a. b. c. d.

VR

I=

IV

R=

RV

I=

Total - 5 marks ( mark each)


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10. Which of the following material can not be used in connecting wires for connecting thecomponents of electric circuit.

a. Aluminium b. Bakelite c. Copper d. Iron

Class Response Assessment Worksheet

Answer Key : Q. No. Correct Choice

1 b

2 b

3 d

4 a

5 b

6 a

7 d

8 d

9 c

10 b


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II. Home work Assessment worksheet

1. How should the two resistances of 2 each be connected so as to produce an equivalentresistance of 1?

2. You are given three resistance of 1, 2 and 3. How with the help of these resistances youcan get 6?

3. In a resistive electric circuit, two resistances are connected in series across a battery of 220V and the voltage drop across one resistance is 150 V, calculate the voltage drop across theother resistance.

4. Judge the equivalent resistance when the following are connected in parallel (i) 1 and106 (ii) 1, 103 and 106

5. Give one advantage of connecting electrical devices in parallel with the battery, instead ofconnecting them in series.

6. What is disadvantage of a series circuit?7. When two resistors of 10 are placed in parallel. Find the current owing in them with a

potential source of 5 Volt.8. When two resistors of 10 are placed in series. Find the current owing in them with a

potential source of 5 Volt.9. Draw a schematic diagram of an electric circuit consisting of a battery of two cells each of

1.5V, 5, 10 and 15 resistor and a plug key, all connected in series.10. What is the effective resistance in the given circuit?

Class Response Assessment Worksheet

Answer Key : Q. No. Correct Choice 1 Parallel combination 2 Series Combination 3 70 v 4 Slightly less than 1 5 Components keep working if one device fails. 6 Circuit breaks if one device fails. 7 0.5 A in each resistor. 8 0.25 A 9

10 5

Total - 10 marks (1 mark each)


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III. Science Quiz : Topic ElectricityObjectives To enable the students to

Revise the concepts given in the chapterRecall the mathematical formula involvedObserve and interpret the graph

Answer the questions based on the content of the chapter

Situation The activity is conducted in the class to cover a chapter /revision of the chapter. Classis divided into teams, a team may contain 10 to 12 students

Time required 15 minutes for a team.Skill developed Thinking, Problem solving, Alertness, Scienti c Attitude, CreativityMaterial Required Blackboard, Chalk, Question bank prepared by teacher, stop watchProcedure (a) Teacher makes clear the rules for quiz to all the teams, as follows.1. There will be three rounds for each team. (detail is given at the end of activity)2. It a team gives wrong answer or no answer then 1 mark will be deducted and bonus marks

will be awarded to answering team.3. Teacher draws a score board on the black board as shown, Tally method can be used for

awarding marks.

Round Team A Team B Team C Team DIst IIII II III2nd III II IIII I3rd II III III III Total

4. Teacher should make effort in a sense so that each student gets minimum one chance toanswer.

5. While getting the answer from the students teacher can make out the weak points of thestudents for the chapter and may plan for his remedial teaching. There will be 3 round inthe quiz:

Ist round, One word answer, ve questions will be asked to each team, 1/2 minutes for eachquestion, Total time needed - 2 minutes.

Example of Questions Total marks-05

Q.1. Name the charge responsible for the conduction in a conductor?

Q.2. What type of connection we use at home?

Q.3. Name the device used to safeguard electrical devices at home?

Q.4. Who is responsible for driving current in a conductor?

Q.5. What is SI unit of electric potential

Q.6. Name the instrument used to measure electric current?


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Round II

2nd round, numerical based questions, ve questions will be asked to each team, 1 minutes foreach question will be given. Student can use pen and paper for computation work.

TOTAL TIME : 5 MINUTES, TOTAL MARKS - 5 (FOR EACH TEAM

Examples for QuestionsQ.1. A conductor of resistance 10 is connected to a cell of emf 2 V. What will be current

following through the conductor?

Q.2. Calculate the amount of heat energy produced in 5 minutes by an electric heater rated at1000w.

Q.3. If the length of conductor having resistivity 1.5 10 -8 Ohm-m is doubled, calculate its newresistivity.

Q.4. An electric bulb is rated 220V and 100W. When it is operated on 110v, what will be thepower consumed?

Round III

3rd round, Rapid re round, True/False type ve question will be asked from each team. 30 secwill be provided for each question Total time needed 2 minutes, Total marks 05

Examples for True/False Questions:State True/False

1. When bulb are connected in series, the lower power bulb glows brighter

2. Nichrome is used for making standard resistances as it readily varies its resistance withtemperature.

3. A body can have a charge less than an electron

4. All Conductors conduct equally.

5. 1kwh is used as unit to compute electricity bill.


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SCIENCE QUIZ

TOPIC ELECTRICITY

Answer Key to Questions

Round I

1. Electron2. Parallel Connection3. Fuse wire4. Cell or Battery5. Volt6. Ammeter

Round II

1. 0.2 A

2. 3 105 J3. No change in resistively4. 50 w

Round III

1. True2. False3. False4. False5. False6. True


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QUESTIONS FOR FORMATIVE ASSESSMENTChemical Reactions and Equations

I. Very short answer questions (V.S.A) (1 mark)1. Arrange the following metals in the decreasing order of reactivity or electro positive character.

K Zn Na Fe Pb Cu2. Which of them will be a reducing agent a metal or non metal?3. Balance the chemical equation

4. Select the combination reaction from following(i)(ii)

5. Select the decomposition reaction from following

(i)(ii)

6. Select the double displacement reaction(i)(ii)

7. Fill in the following about reactivity series of metal : The . Metal replaces the . Metal from its salt solution.

8. Which of the following is not the necessary condition for rusting(i) Presence of oxygen (ii) Presence of catalyst (iii) Presence of moisture

9. Which of the following is required for prevention of corrosion:(i) coating of less electropositive metal(ii) coating of more electropositive metal

10. Choose the correct about rancidity(i) Rancidity is a reduction process(ii) Rancidity is an oxidation process


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Answer Key1. K > Na > Zn > Fe > Pb > Cu2. Non metal3.4.

5.6.7. Strong, Weak 8. Presence of catalyst9. Coating with move electropositive metal10. Rancidity is an oxidation process

II. Short answer type questions SA, (2 marks)1. What happens when aqueous solution of Barium chloride is added to aqueous sodium

sulphate solution?2. When silver coloured metal (A) is added to dilute sulphuric acid, solution (B) is formed which

is colourless solution and a gas (c) is evolved which is colourless name A, B and C and writethe equation?

3. An A blue coloured crystalline salt on heating decomposes to B white substance. W hen inblue salt solution, a metal (Zinc) is added, its gives rise to colourless solution C wth leavingbehind D reddish brown metal.Name the compounds A, B, C and D

4. A mixture of Chromium Oxide is heated with Aluminum powder on strong heata. Write the reacton?b. Give one application of this reaction?

5. De ne Rusting?Give two methods of protection of metal trans rusting.

Answer Key1. White precipitate of BaSO4 is obtained. Reaction will be as 2. A is Zinc, B is ZnSO4 solutions C is H2gas and reactions will be 3. A, B, C, and D are respectively- CuSO4, 5 H2O, CuSO4, ZnSO4 (aq), Cu (s)4. (i)

(ii) This reaction is used in termite welding5. (i) Rusting is a slow electrochemical process in which hydrated oxide of metal in formed from

metal when it comes in with air moisture(ii) By Painting, by galvanization, by tinning


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Short Answer type Questions SA2 (3 marks)1. Convert the statement into balanced equations by hit and trial method.

a.b.c.

2. Balance the following skeleton equation by hit and trial method a.

b.c.

3. Select the oxidizing and reducing agent from the following:4. De ne oxidation. Give equations showing addition of oxygen and removal of hydrogen.5. De ne reduction. Give equations showing removal of oxygen and addition of hydrogen.

Answer Key

1. (i)(ii)(iii)

2. (i)(ii)(iii)

3. (i) H2S is reducing agent and I2 is oxidizing agent(ii) CuO is oxidizing agent and H2 is reducing agent(iii) Zn is reducing agent and CuSo4 is oxidizing agent

4. Oxidation is dened as addition of oxygen to an element or compound or the removal ofhydrogen from a compound.Addition of oxygen

Removal of Hydrogen

5. Reduction is addition of hydrogen or removal of oxygen from a compound.

Addition of Hydrogen

Removal of Oxygen


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Long Answer Type Questions (5 marks)1. (i) Explain the term corrosion?

(ii) Write the chemical reaction of corrosion of Iron?(iii) Name two metals which corrodes easily?(iv) Aluminum corrodes in moist air but is widely used is making utensils.

(v) what is galvanization and why do we use Zn for it?\2. (i) What is rancidity? Where does it happen

(ii) what are anti oxidants? Why are they added fat and oil containing food to prevent fromrancidity?

(iii) why do most items pu ed with nitrogen.

Answer Key1. (i) The process of slow destruction of metals when exposed to air, moisture and pollutant

gases , in called as corrosion.(ii)(iii) Formation of green coating on copper and formation of thin layer of oxide on aluminum

are example of corrosion.(iv) Aluminum forms oxide layer on exposure to air, this oxide layer further checks

corrosion.(v) Galvanization is a process in which Zinc layer is applied on Iron. It is used to protect iron

from rusting.2. (i) The oxidative deterioration of oils and fats leading to stinking smell or stale taste is known

as rancidity.(ii) Anti Oxidants are those chemicals which an addition to fat and oil checks it from rancidityan

addition of anti oxidants fatty food is protected from stale.(iii) Nitrogen is lled in potato chips & other food to create anaerobic (air free atmosphere)

which avoids rancidity.


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QUIZ COMPETITION

Instructions :1. There will be four teams , team A, team B, team C and team D in all.2. All the students will be equally divided in four rows of seating arrangement

3. There will be three rounds in all and 60 questions in M.C.Q., one word and rapid re round4. First round will comprise of four alternatives, in which one will be the correct answer. Such

20 questions will be of 40 points.5. The questions will be asked rst to team A than to team B, team C and team D.6. If one team fails to answer, question will be asked to next team. If this team answers correctly,

Bonus points will be given to this team other wise question will be passed to next teams,Bonus points is of one point.

7. Each team one by one will get an opportunity for M.C.Q type of questions in rst round.8. Second round will be of one word or one sentence. Answer will be sought as in rst round

from each team along with bonus point criteria as above.9. Third round will be rapid re round, in which from each team 20 questions will be asked

without any Bonus point round10. In all the rounds, team will have 04 students for M.C.Q, 04 students for one word and only

one (01) students for rapid re round from each team. i.e. on the stage from each team 09students can participate.

11. Each team in between each round will have a break of 05 minutes for team discussion.12. For each question only thirty seconds will be limited to answer otherwise question will be

passed for next time.

1. First Round M.C.Q1. Choose the double displacement reaction

(a)(b)(c)(d)

2. When in a chemical reaction, a product is obtained as a precipitate, it is shown by thefollowing sign(a)

(b)(c)(d)

3. KCIO KCI

(a) Combination Reaction(b) Decomposition Reaction(c) Displacement reaction(d) Double displacement reaction


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4. Which one of the below given reaction is balanced(a)(b)(c)(d)

5. The above reaction is an example of a :(a) Combination reaction(b) Double decomposition reaction(c) Decomposition reaction(d) Displacement reaction

6. On heating of Lead nitrate, a specic sound is heard on decomposition of lead nitrate.(a) musical sound(b) thunder sound(c) Crackling sound(d) all are correct

7. Which one is not observed when a clean nail of iron is added to a solution of copper sulphatein water?(a) a brown material is deposited on iron nail(b) blue colour of copper sulphate fades.(c) after sometime bule solution become greenish.(d) a blue material is deposited on iron nail?

8. Which is correct about exothermic reactions?(a) heat is absorbed.(b) temperature of surounding decreases(c) heat is neither absorbed nor evolved(d) heat is evolved in the reaction

9. Which of the below given reaction is thermic reaction(a)(b)(c)(d)

10. Which one is correct about skeleton reaction(a) skeleton reaction is balanced reaction(b) skeleton reaction is a translation of statement in equation form.(c) Skeleton reaction have statement and formula both.(d) all are correct.


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11. What is most appropriate statement about decomposition reaction given below:(a) it is reverse of combination reaction(b) it may have thermal decomposition(c) it has electrolytic decomposition(d) all are correct

12. which one of the following is not a decomposition reaction(a)(b)(c)(d)

13. Which one of the following & reaction is incorrect as per reactivity series of metals:(a)(b)(c)(d)

14. Which is not suitable conditions for rusting-(a) Presence of Oxygen(b) Absence of Oxygen(c) Presence of water or moisture(d) Presence of pollutant gases like Cu 2, SO2 and NO 2.

15. What is not correct about rusting of iron?(a) It is an Oxidation Reaction

(b) It is a slow reaction(c) It forms blue coloured oxide.(d) It is a hydrated oxide of iron.

16. Which one is a correct statement about the reaction.SO

(a) Iron is more reactive than copper(b) Iron is less reactive than copper(c) In this reaction Cu 2+ ion is oxidised(d) copper is same reactive as iron.

17. Which one is a correct statement about the reaction

(a) Cu2+ (aq) is reduced to Cu (s)(b) Zn2+ (aq) is reduced to Zn (s)(c) Cu2+ is reduced to Cu (s) and a Zn (s) in oxidised to Zn 2+ (aq)(d) All are correct

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