Hello dear, as you want KVPY Interview Questions Physics here I’m providing you few interview question with their answer for KVPY exam.

Here are KVPY Interview Questions Physics:

KVPY(Physics)

1. What are the orders of drift velocity for normally applied potentials (0 to 5V) and that of random thermal speed at room temperature say (300 K).
Ans. The drift velocity is of the order of 10m per second whereas random thermal velocity of electrons is of the under of 105 metre per second.

2. What is the conventional direction of flow of current in a metallic conductor ?
Ans. The conventional direction of flow of current is taken as the direction of flow of positive charge from higher potential to lower potential.

3. What is meant by ampere hour capacity of a cell ?
Ans. It is a measure of the electricity capacity of a cell, i.e., how much quantity of electricity a cell is capable of supplying. It is measured by the product amperes x hours.

4. What do you mean by 10 A × h ?
Ans. 10 A × h means, the cell will supply 1 A current upto 10 hours. 2 A current upto 5 hours or 0.5 A current upto 20 hours.

5. Which one is greater -e.m.f. or terminal p.d. across the cell ?
Ans. The e.m.f. is greater than the potential difference across the cell e.m.f.

6. Is it possible in any case where p.d. > e.m.f. of the cell ?
Ans. Yes, at the charging of the cell

7. Can you measure e.m.f. of a cell with a voltmeter ?
Ans. No, because it requites some current from the cell for its reading. (it is measured by potentiometer)

8. When is the Wheatstone’s bridge said to be most sensitive ?
Ans. When all the four resistances P, Q, R and S are of nearly the same order of magnitude.

9. Define figure of merit of galvanometer ?
Ans. The figure of merit which is defined as the current required to produce a deflection of one division in the galvanometer. ( k = I/).

10. Define current sensitivity and voltage sensitivity.
Ans. Current sensitivity = /I and voltage sensitivity = /V

11. How can you measure alternating current ?
Ans. Heating effect of current, Q = I2.R.t. is independent of the direction of flow of current because I2 would always be positive. Therefore, Hot Wire ammeter is used for this purpose.

12. Suppose you have been given two tuning forks of the same metal on which marks of the frequency have disappeared. How will you detect the one with higher frequency?
Ans. The one which has smaller prongs will be of higher frequency.

13. What do you mean by a note ? How does it differ from a tone ?
Ans. A tone is simple sound resulting from a pure simple harmonic motion. On the other hand a note is a complex sound made up of a complex periodic motion as obtained by the superposition’s of a number of pure simple harmonic motions.

14. If the prongs of a fork are rubbed with a file slightly or prong of tuning fork is loaded with wax than what will be the change in frequency in both the cases.
Ans. Frequency will decreases in both the cases.

15. If you set your watch by the sound of a distant siren, will it go fast or slow ?
Ans. go slow, [because, sound take some finite time to reach you]

16. When we start filling an empty bucket with water the pitch of the sound produced goes on changing, why ?

20. the ball of a pendulum is hollow and filled with water. A small hole is made in the bottom of the ball, water comes out from it. How the time period of pendulum will effect.
Ans. First it will increase then decrease.

21. If we increase the current drawn from the cell then what will be the effect on potential difference across the cell ?
Ans. V = E– Ir, it will decrease

22. A car is moving towards north direction with speed V. What will be the induced emf in the axle of the car. If it is moving towards east, what will be the emf induced in the axle.
Ans. (i) V is towards north emf induced due to BH
So, e = 0 )j ˆ B j ˆv .( i ˆ   H 
emf induced due to BV
) k ˆ B ( j ˆv .[ i ˆ    V = – BV v
(ii) Car is moving towards east
so, emf due to BH
e = 0 )j ˆ B i ˆV ( j ˆ    H 
due to BV
e = )] j ˆ ( B i ˆ V [ j ˆ    V  = 0

23. What are soft and hard x-rays ? Why are they so called ?
Ans. 0.1 to 1 Å hard x-rays, 1 to 10Å soft x-rays

24. On which experiment Kepler’s laws are based ?
Ans. Tycho brahe’s experiments

25. If the earth is at one-fourth of its present distance from the sun, then what will be the duration of year ?
Ans. 1/8 the present year

26. Who was the first to introduce MKS system ?
Ans. Giorgi

27. A liquid boils at a temperature of which its saturated vapour pressure becomes ?
Ans. Equal to the atmospheric pressure.

29. What will be kinetic energy of molecules of 1g He gas at 100ºC ?
Ans. 1200 joule

30. A particle of charge +q is dropped from rest above a height ‘h’ from the surface of a uniformly charged sphere of charge +Q and radius R. When will be the particle hit the surface of the sphere?
Ans. Hit the surface only if h is large enough.