Wave Optics — Physics STD 12 Science — Question

The impurity atoms with which pure silicon may be doped to make it a p-type semiconductor are those of:

The electric potential inside a conducting sphere:

Susceptibility is positive and large for a:

During a nuclear fusion reaction:

The self inductance of a coil is 5 henry, a current of 1 amp change to 2 amp within 5 second through the coil. The value of induced e.m.f. will be

(a) 10 volt

(b) 0.10 volt

(c) 1.0 volt

(d) 100 volt

The Sun receives its radiation energy from :

The ratio of areas within the electron orbits for the first excited state to the ground state for hydrogen atom is

(a) 16 : 1

(b) 18 : 1

(c) 4 : 1

(d) 2 : 1

In a process on a system, the initial pressure and volume are equal to the final pressure and volume.

1. The initial temperature must be equal to the final temperature.
2. The initial internal energy must be equal to the final internal energy.
3. The net heat given to the system in the process must be zero.
4. The net work done by the system in the process must be zero.

If the frequency of light in a photoelectric experiment is doubled, the stopping potential will:

1. Be doubled.
2. Be halved.
3. Become more than double.
4. Become less than double.