S lss 12 t sis Sol ti r 2015 St 1 - KopyKitab · S lss 12 t sis Sol ti r 2015 St 1 The Practice...

1

Get CBSE Syllabus, NCERT Solutions, Sample papers, Practice papers, Guess Papers, Solved Question Papers, Online Tests And Much More…

CBSE Class 12th Physics Solved Practice Paper 2015 Set 1

2



The Practice Paper is a product of CBSE Class 12th Board exam experts of jagranjosh.com, an online educational portal of Dainik Jagran.

After a round analysis for the previous four years of CBSE Class 12th Board Physics Question papers, the jagranjosh.com experts have set this Practice Paper for the 2015 CBSE Class 12th Boards.

An analysis of Previous Years Physics Question Papers has been mentioned here:

PREFACEPREFACE

http://www.jagranjosh.com/cbse



3



Below are the Chapters covered under the entitled units:

This conceptual Practice Paper along with guided solutions is a product exclusively for CBSE Class 12th students. The pattern of the Practice Paper is as per the Previous Year’s CBSE Board Physics Question Papers, thus the students will find it easy and understandable in all its aspects.

4



Copyright ©Jagranjosh.com

All rights reserved. No part or the whole of this eBook may be copied, reproduced, stored in retrieval system or transmitted and/or cited anywhere in any form or by any means (electronic, mechanical, photocopying, recording or otherwise), without the written permission of the copyright owner. If any misconduct comes in knowledge or brought in notice, strict action will be taken.

Disclaimer

Readers are requested to verify/cross-check up to their satisfaction themselves about the advertisements, advertorials, and external contents. If any miss-happening, ill result, mass depletion or any similar incident occurs due to any information cited or referenced in this e-book, Editor, Director/s, employees of Jagranjosh.com can’t be held liable/responsible in any matter whatsoever. No responsibilities lie as well in case of the advertisements, advertorials, and external contents.

Free Checklist for the Year 2015 for Class 12th Physics:• Syllabus• Chapter-wise Tips & Strategy• Chapter-wise NCERT Solution• Chapter-wise Online Test• Sample Paper• Solved Practice Paper• Solved Guess Paper• Guess Paper• Stress Management• Time Management• Further Career Options

http://www.jagranjosh.com/articles/cbse-class-12-physics-syllabus-2014-1351849798-1

http://www.jagranjosh.com/articles/tips-strategies-for-cbse-class-12-physics-1384343147-1

http://www.jagranjosh.com/articles/ncert-solutions-for-class-12-physics-1381472495-1

http://www.jagranjosh.com/cbse-free-online-test-st-1376892747%23sthash.TqcT7HN4.tgYBW1z1.dpbs

http://www.jagranjosh.com/articles/cbse-class-12-physics-sample-paper-2013-1353305091-1

http://www.jagranjosh.com/articles/cbse-class-12th-physics-solved-practice-paper-2015-1418127946-1

http://www.jagranjosh.com/articles/cbse-class-12th-physics-solved-guess-paper-2014-1392638733-1

http://www.jagranjosh.com/articles/cbse-class-12th-guess-papers-1386399915-1

http://www.jagranjosh.com/articles/ways-to-avoid-stress-during-class-12-board-exams-1300278213-1

http://www.jagranjosh.com/articles/how-to-manage-time-in-class-12-board-exams-1305263410-1

http://www.jagranjosh.com/articles/career-options-availability-after-cbse-class-12th-science-1366288377-1

5



‘SECTION – A’

Q 1. When does a charged circular loop behave as a point charge?

Q 2. A current carrying loop free to turn is placed in a uniform magnetic field B

. What will be its orientation relative to B

in equilibrium state?

Q 3. What is wattles current?

Q 4. The refractive index of glass is 1.5. What is the velocity of light waves in the glass?

Practice Paper - 2015Class: XII

Subject: PhysicsSet -1

Time Allowed: 3Hours Maximum Marks: 70

General Instructions:

(i) All questions are compulsory.(ii) There are 29 Questions in all.(iii) Question numbers 1 to 8 carry 1 mark each.(iv) Question numbers 9 to 16 carry 2 marks each.(v) Question numbers 17 to 26 carry 3 marks each.(vi) Question numbers 27 to 29 carry 5 marks each. (vii) Internal choices have been provided in some questions. Use Log Tables, if necessary.

6



Q 5. Plot a graph between de-Broglie wavelength (λ) and momentum (ρ) of a particle.

Q 6. Can a straight wire act as an inductor?

Q 7. Explain why the spectrum of the hydrogen atom has many lines, although a hydrogen atom contains only one electron.

Q 8. In what way is diffraction from each slit related to the interference pattern in a dou-ble-slit experiment?

‘SECTION – B’

Q 9. A circular brass loop of radius a and resistance R is placed with its plane perpendicular to a magnetic field, which varies with time as o sinB B tω= . Obtain the expression for the induced current in the loop.

Q 10. The battery remains connected to a parallel plate capacitor and a dielectric slab is inserted between the plates. What will be the effect on its (i) capacity, (ii) charge, (iii) potential difference, (iv) electric field, and (v) energy stored? Justify your answer.

Q 11. In a single slit diffraction experiment, the width of the slit of the slit is made double the original width. How does this affect the size and intensity of the central diffrac-tion band? Draw a plot of the intensity distribution?

Q 12. Why is it that while using a moving coil galvanometer as a voltmeter a high resistance in series is required whereas in an ammeter a shunt is used?

7



Q 13. You are given a 2 µF parallel plate capacitor. How would you establish an instanta-neous displacement current of 1 mA in the space between its plates?

Q 14. Write the truth table for circuit given in the figure below consisting of NOR gates and identify the logic operation (OR, AND and NOT) which this circuit is performing.

OR

Can we take one slab of p-type semiconductor and physically join it to another n-type semiconductor to get p-n junction?

Q 15. An alternating voltage given by V =140 sin 314t is connected across a pure resistor of 50 ohm. Find (i) the frequency of the source. (ii) the rms current through the resistor.

Q 16. Why are microwaves used in RADAR technology?

‘SECTION – C’

Q 17.

(a) Obtain an expression for magnetic energy stored in a solenoid in terms of magnetic field B, area A and length l of the solenoid.

(b) How does this magnetic energy compare with the electrostatic energy stored in a ca-pacitor?

8



Q 18. An object is placed (i) 10 cm, (ii) 5 cm in front of a concave mirror of radius of cur-vature 15 cm. Find the position, nature and magnification of the image in each case.

OR

An equi-convex lens, with radii of curvature of magnitude 10 cm each, is put over a

liquid layer poured on top of a plane mirror. A small needle, with its tip on the prin-cipal axis of the lens, is moved along the axis until its inverted real image coincides with the needle itself. The distance of the needle, from the lens, is measured to be 15 cm. On removing the liquid layer, and repeating the experiment, the distance is mea-sured to be 10 cm.

Given that the two values of the distance measured represent the focal length values in the two cases, calculate the refractive index of the liquid.

Q 19. A prism is made of glass of unknown refractive index. A parallel beam of light is in-cident on a face of the prism. By rotating the prism, the minimum angle of deviation is measured to be 400. What is the refractive index of the prism? If the prism is placed in water (µ = 1.33), predict the new angle of minimum deviation of the parallel beam. The refracting angle of prism is 600.

Q 20. Prove that energy is conserved in interference?

Q 21.

(a) The near point of a hypermetropic person is at 75 cm from the eye. What is the power of the lens required to enable him to read clearly a book held at 25 cm from the eye?

(b) In what way does the corrective lens help the person above? Does the lens magnify objects held near the eye?

(c) The person above is preferred to remove his spectacles while looking at the sky. Ex-plain why?

9



Q 22. A parallel plate capacitor with circular plates of radius 1 m has a capacitance of 1 m has a capacitance of 1 nF. At t = 0, it is connected for charging in series with a resis-tor R = 1 MΩ across 2 V battery. Calculate the magnetic field at a point P, half way between the centre and the periphery of the plates as shown in figure after 10–3 sec. (You may start by assuming that the charge on the capacitor at time t is, q (t) = CV [1 – exp. (–t/τ)], where the time constant τ is equal to CR).

Q 23. Two Polaroids A and B are kept in a crossed position. How should a third Polaroid C be placed between them so that the intensity of polarised light transmitted by Pola-

roid B reduces to 18

th of the intensity of unpolarised light incident on A?

Q 24. The total energy of an electron in the first excited state of the hydrogen atom is about 3.4 eV.

(a) What is the kinetic energy of the electron in this state?

(b) What is the potential energy of the electron in this state?

(c) Which of the answers above change if the choice of the zero of potential energy is changed?

10



Q 25.

(a) State Einstein’s photoelectric equation and give the characteristic properties of pho-tons on which this equation is based.

(b) On the basis of this equation explain three observable features.

Q 26.

(a) With the help of a schematic diagram, explain the principle behind the working of the Van de Graff generator.

(b) Is there any restriction on the upper limit of the high voltages set up in this machine? Explain.

‘SECTION – D’

Q 27.

(a) Derive the expression for the magnetic field in the vector form at a point on the axis of a circular current loop, using Biot - Savart Law?

(b) What does a toroid consist of? Find out the expression for the magnetic field inside a toroid for N turns of the coil having the average radius r and carrying a current I. Show that the magnetic field in the open space inside and exterior to the toroid is zero.

OR

(a) A rectangular coil of sides 8 cm and 6 cm having 2000 turns and carrying a current of 200 mA is placed in a uniform magnetic field of 0.2 T directed along the positive x-axis.

(i) What is the maximum torque the coil can experience? In which orientation does it experience the maximum Torque?

CBSE Class 12th Solved PhysicsPractice Paper 2015 (Set-I)

Publisher : Jagran Josh Author : Jagran Josh Expert

Type the URL : http://www.kopykitab.com/product/8245

Get this eBook

40%OFF

http://www.kopykitab.com/CBSE-Class-12th-Solved-Physics-Practice-Paper-2015-Set-I-by-Jagran-Josh-Expert

S lss 12 t sis Sol ti r 2015 St 1 - KopyKitab · S lss 12 t sis Sol ti r 2015 St 1 The Practice...

Documents

Transcript of S lss 12 t sis Sol ti r 2015 St 1 - KopyKitab · S lss 12 t sis Sol ti r 2015 St 1 The Practice...