## 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.

## Physics Class tests for Junior college (PUC/ISc/XII/CBSE/ICSE)

Question 7

(a) Cyclotron frequency is proportional to energy (b) depends on magnetic field

Question 8

Angular Momentum L is an integral multiple of which constant?

(a) Fine structure constant

(b) Rydberg Constant

(c) Universal Gas Constant

(d) Planck’s Constant

Question 9

Ground state speed of e- in the H-atom in terms of speed-of-light c is

(a) c/137 (b) c.137 (c) a.c/137 (d) c/10

Question 10

Whats the energy of H-atom according to Niels Bohr?

(a) -13.61/n2 eV (b) +13.61/n2 eV (c) -13.61/n eV (d) -13.61 eV

## Homework questions of Physics for Junior college (PUC, ISc, XII, CBSE, ICSE)

Question 3

Deuteron is a bound state of a neutron (n) and a proton (p) with a binding energy BE = 2.2 MeV. A g-ray of energy E is aimed at a deuteron nucleus to try to break it into a neutron and proton so that n and p move in direction of incident g ray. If E = B.E. show that this is not possible. How much should BE be so that such a process can occur.

Question 4

Total charge –Q is uniformly distributed along length of a ring of radius R. A small test charge = q of mass m is kept at center of ring and is given a gentle push along the axis of the ring.

## Physics for XII, ICSE. Preparatory Test for Quarterly.

15. Describe the Rutherford atomic model by explaining results of Geiger Marsden scattering experiment. Draw a PE, KE, E diagram of a Rutherford H-atom. Draw the Marsden scattering experiment plot and Gold-foil alpha-particle deflection diagram and explain each with 1 or 2 sentences. What are the drawbacks of this model? (2 is enough)

16. Use the Bohr’s n-th level energy -13.61/n2 eV to find the energy of absorption from n=2 to n =6 state and energy of emission from n=5 to n=3 state.

17. Describe the Van-de-Graf generator, its principle, working and use.

## Class XII, CBSE exam questions, Physics, Preparatory for Quarterly Exam.

1. Where would Coulomb’s interaction be weaker in dielectric medium or vacuum?

2. Between dipole and a point charge whose Electric Potential reduces faster?

3. What is the work done when a charge makes a rectangular path on an equi-potential surface?

4. Write the de-Broglie formula for wavelength of a wave-particle if its momentum is p?

5. Define refractive index from angle of incidence and angle of reflection.

## Class XII, CBSE exam questions, Physics, Updated Version 2

6. State how density of electric lines of force is related to the Electric Field Vector intensity E. Also mention another three properties of the lines of forces.

7. Write the vector expression for Coulomb’s law and state 3 forces that are conservative forces by nature.

8. How one defines the direction of a Dipole Vector? Define a unit dipole vector p. Write the expression for dipole vector by using p and the magnitude of charge = 3 Q and separation between the charge as 1 Angstrom.

9. What’s the energy of an alpha particle if we place it in a potential difference of 100 Volt assuming its at rest at this location? What will be the energy of a proton if its placed at the same location at rest.