Question

2. Answer the following questions :
[8]
(i) A uniform disc and a hollow right circular cone have the same formula for
moment of inertial for rotation about their corresponding central symmetry
axes. Why is it so?
(ii) What sets the limit on the efficiency of a heat engine?
(iii) A particle performs linear SHM of amplitude 5 cm. At what displacement
from its mean position will the potential energy of the particle be 20% of its
total energy?
(iv) What is balance point' in Kelvin’s method of determination of galvanometer
resistance?
(1)
(v) What is the magnetic moment of an electron due to its orbital motion?
(vi) Find the Brewster angle for light reflected from glass active
index 3.
(vii) What is photoelectric effect?​

Answer 1

Answer:

A uniform disc and a hollow right circular cone have same formula for their moment of inertia.This is because when a hollow right circular cone is cut along its slanting side and the metal is stretched out, you will find that the surface of the cone will form a circle.

2)he temperature of the cold reservoir sets the limit on the efficiency of a heat engine.

3)The total energy is

T=\frac12kA^2.T=  

2

1

​  

kA  

2

.

4)Then the jockey slides over the meter bridge points at the two extreme edges, and checks if the galvanometer shows deflection on both sides. Now, the jockey is slid to such a point, where the galvanometer shows no deflection. This point is called the balance point.

5)n atomic physics, the electron magnetic moment, or more specifically the electron magnetic dipole moment, is the magnetic moment of an electron caused by its intrinsic properties of spin and electric charge. The value of the electron magnetic moment is approximately −9.284764×10−24 J/T.

6)The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. Electrons emitted in this manner are called photoelectrons.

Explanation: