nvsrochd.gov.in : Class XII Physics Question Paper nvsrochd.gov.in
Board : Navodaya Vidyalaya Samiti
Exam : Class XII Physics
Document Type : Study Material
Website : nvsrochd.gov.in
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Physics Sample Question Paper :
Class – XII
Max Marks : 70
TIME : 3h
Related : Navodaya Vidyalaya Samiti Class XII English Question Paper : www.pdfquestion.in/6615.html
General Instructions
(a) All questions are compulsory.
(b) There are 30 questions in total. Questions 1 to 8 carry one mark each, questions 9 to 18 carry two marks each, questions 19 to 27 carry three marks each and questions 28 to 30 carry five marks each.
(c) There is no overall choice. However, an internal choice has been provided in one question of two marks, one question of three marks and two questions of five marks each. You have to attempt only one of the given choices in such questions.
(d) Use of calculators is not permitted.
(e) You may use the following physical constants wherever necessary :
c = 3 x 108ms-1 ;
h = 6.6 x 10-34Js ;
e = 1.6 x 10-19 C
µo = 4 p x 10-7T m A-1 ;
Boltzmann constant k = 1.38 x 1023 JK-1
Avogadro’s number NA = 6.023 x 1023/mole
Mass of neutron mn = 1.6 x 10-27 kg
1.If the number of turns and the length of a solenoid are doubled keeping the area of cross section same, how is the inductance affected?
2.Draw a labelled diagram of Simple microscope.
3.A variable frequency a.c. source is connected to a capacitor. Will the displacement current increase or decrease with increase in frequency?
4.The current sensitivity of a moving coil galvanometer is 5 division/mA and voltage sensitivity is 20 division/volt. Find the resistance of the galvanometer.
5.The divisions marked on the scale of an ac ammeter are not equally spaced. Why
6.The forbidden energy gaps in insulators, semiconductors and conductors are EG1 , EG2 and EG3 respectively. Arrange them in ascending order.
7.What is the relation between power gain, voltage gain and current gain and current gain of a transistor amplifier?
8.Write two important characteristics of nuclear forces.
9.The given graph shows the variation of charge q versus potential difference ‘V’ for two capacitors C1 and C2. The two capacitors have same plate separation but the plate area of C2 is double than that of C1. Which of the lines in the graph correspond to C1 and C2 and why? 2
10. The storage battery of a car has an emf of 12 V. If the internal resistance of the battery is 0.4 Ω, what is the maximum current that can be drawn from the battery?
11. Name materials, one in each case, which are suitable for
a. permanent magnet &
b. core of an electric transformer, Justify your answer
12. Name the waves that are often referred to as ‘heat waves’. Name the physical quantity that has:
a. higher,
b. lower
c. same value for these waves, as compared to X-rays. 2
13a. In a metre bridge, the balance point is found to be at 39.5 cm from the end A, when the resistor S is of 12.5 O. Determine the resistance of R.
b.Determine the balance point of the bridge above if R and S are
14. A ray of light passes through a prism in the position of minimum deviation. Trace the path of the reflected ray. What is the inclination of the ray (inside the prism) with the base of the prism.
15.The ionization energy of hydrogen atom is 13.6 eV. Following the Bohr’s theory, find the energy corresponding a transition Calculate the shortest and the longest wavelength emitted in the Balmer Series.
Or
16.A 100W sodium lamp radiates energy uniformly in all directions. The lamp is located at the centre of a large sphere that absorbs all the sodium light which is incident on it. The wavelength of the sodium light is 589 nm.
a.What is the energy per photon associated with the sodium light?
b.At what rate are the photons delivered to the sphere?
17.Consider an optical communication system operating at . Suppose, only 1% of the optical source frequency is the available channel band-width for optical communication. How many channels can be accommodated for transmitting audio-signals requiring a band-width of 8 kHz.
18. de-Broglie wavelength associated with an electron What will be its wavelength, when the accelerating potential is increased to 4 V?
19.Consider a uniform electric field E = 3 × 103 î NC-1.
(a) What is the flux of this field through a square of 10 cm on a side whose plane is parallel to the yz plane?
(b) What is the flux through the same square if the normal to its plane makes a 60° angle with the x-axis?
20a. For circuits used for transporting electric power, a low power factor implies large power loss in transmission. Explain.
b. A lamp is connected in series with a capacitor. Predict your observations for d.c. and a.c. connections. What happens in each case if the capacitance of the capacitor is reduced? 3
OR
An alternating voltage and the corresponding current are given by = 110 sin( + /6) and I = 5 sin( – /6) respectively. Find the impedance and the average power dissipation in it.