# physics questions

## A Question a Day (series) Q3

The equation v = a*del_t is sometimes used
to find velocity when acceleration and
time are known. Another form of this
equation is v = v_0 + a*del_t. In this second
form of the equation, the function of the
term v_0 is to:

A. indicate that the equation is valid
only for an object that starts at rest.

B. determine the time at which
velocity is equal to zero.

## A Question a Day (series) Q2

1. A ball is thrown with an initial velocity of 20 m/s at an angle of 30°
above the horizontal. What is the instantaneous vertical velocity of
the ball when it is 5.1 m above the release point? (g = 9.8 m/s^2)

A. 0.2 m/s
B. 6.6 m/s
C. 10 m/s
D. 17 m/s

## Physics Midterm for ISc-II (ICSE) [also good for CBSE/PU-II]

(c) Fission of U – 235 nucleus releases 200 MeV of energy. Calculate the fission rate (i.e. no. of fissions per second) in order to produce a power of 320 MW.

Q 10:

(a) What’s the ratio of the shortest wavelength of Balmer series to the shortest wavelength of the Lyman series?

(b) What are the (i) energy (ii) magnitude of momentum, and (iii) wavelength of the photon associated with spectral emission of H-atom transition; n=3 state to n=1 state?

## Physics class tests, XII/ICSE/CBSE

3. Why Ka and Kb lines are produced (chose only one appropriate answer)

A. electronic transitions B. Atomic collisions

C. Radioactive decay D. Nuclear transmutation

4. Exactly why there is quantization of physical variables such as momentum, angular momentum, energy, orbital distance and speed?

A. wave-particle duality B. Interference of waves

C. Particle acceleration to speed of light D. Resistance experienced by particles in conductors

5. Cathode rays are streams of

A. electrons B. x-rays

C. nucleons D. high atomic number elements

## Physics class tests for XII/ICSE/CBSE

Question 1

Derive potential due to an electric dipole in a general direction making an angle J with dipole axis. Use E = -dV/dr to obtain E in general direction.

Question 2

Derive electric field in the end-on and broad-on position for a dipole vector P = p 2Q.a, where P is the vector and p the unit vector along the same.

Question 3

Describe the Rutherford’s model of the atom. Explain the results of the Geiger-Marsden experiment with a diagram. Mention the Rutherford’s model’s drawback.