Name of the Board : CBSE Academic
Class : XII STD
Document Type : Sample Question Paper
Subject : Physics
Year : 2017-18
Website : http://cbseacademic.nic.in/SQP_CLASSXII_2017_18_final.html
Download Sample Question Paper : https://www.pdfquestion.in/uploads/22447-Physics-SQP.pdf
Marking Scheme : https://www.pdfquestion.in/uploads/22447-Physics-MS.pdf
Physics Sample Question Paper :
General Instructions :
1. All questions are compulsory. There are 26 questions in all.
Related / Similar Question Paper : CBSE XII Commercial Art Question Paper 2017-18
2. This question paper has five sections – Section A, Section B, Section C, Section D and Section E.
3. Section A contains five questions of one mark each, Section B contains five questions of two marks each, Section C contains twelve questions of three marks each, Section D contains one value based question of four marks and Section E contains three questions of five marks each.
4. There is no overall choice. However, an internal choice has been provided in one question of two marks, one question of three marks and all the three questions of five marks weightage. You have to attempt only one of the choices in such questions.
5. You may use the following values of physical constants wherever necessary.
c = 3 X 108 m/s
h = 6.63 X 10-34 Js
e = 1.6 X 10-19 C
μo = 4 X 10-7 T m A-1
𝛆0 = 8.854 X 10-12 C2 N-1 m-2
= 9 X 109 N m2 C-2
me = 9.1 X 10-31 kg
mass of neutron = 1.675 X 10-27 kg
mass of proton = 1.673 X 10-27 kg
Avogadro’s number = 6.023 X 1023 per gram mole
Boltzmann constant = 1.38 X 10-23 JK-1
Section – A :
1. In the given figure, charge +Q is placed at the centre of a dotted circle. Work done in taking another charge +q from A to B is W1 and from B to C is W2. Which one of the following is correct: W1 > W2, W1=W2 and W1 < W2?
2. Plot a graph showing the variation of current ‘I’ versus resistance ‘R’, connected to a cell of emf E and internal resistance ‘r’.
3. State the factors on which the refractive index of a material medium for a given wavelength depends.
4. Sketch the emergent wavefront.
5. In the wave picture of light, intensity of light is determined by square of the amplitude of wave. What determines the intensity of light in the photon picture of light?
Section – B :
6. (a)An alternating voltage E = Eo sinωt is applied to a circuit containing a resistor R connected in series with a black box. The current in the circuit is found to be I = Io sin (ωt + π/4).
(i) State whether the element in the black box is a capacitor or inductor.
(ii) Draw the corresponding phasor diagram and find the impedance in terms of R.
7. The magnetic field in a plane electromagnetic wave is given by :
By = 12 × 10–8 sin (1.20 × 107 z + 3.60 × 1015 t) T. Calculate the
(i) Energy density associated with the Electromagnetic wave
(ii) Speed of the wave
8. A spherical convex surface of radius of curvature 20 cm, made of glass (μ = 1.5) is placed in air. Find the position of the image formed, if a point object is placed at 30 cm in front of the convex surface on the principal axis.
9. Name the optoelectronic device used for detecting optical signals and mention the biasing in which it is operated. Draw its I- V characteristics.
10. Give reason, why high frequency carrier waves are needed for effective transmission of information signals.
OR
What is the range of frequencies used for T.V. transmission? State two factors by which the range of TV signals can be increased.
Section – C :
11. (a)How many electrons must be added to one plate and removed from the other so as to store 25.0 J of energy in a 5.0 nF parallel plate capacitor?
(b) How would you modify this capacitor so that it can store 50.0 J of energy without changing the charge on its plates?
12. A point charge +Q is placed at the centre O of an uncharged hollow spherical conductor of inner radius ‘a’ and outer radius ‘b’. Find the following :
(a) The magnitude and sign of the charge induced on the inner and outer surface of the conducting shell.
(b) The magnitude of electric field vector at a distance (i) r = , and (ii) r = 2b, from the centre of the shell.