Semiconductor Electronic: Material, Devices And Simple Circuits — Physics STD 12 Science — Question

Which of the following statement is false(a) Heat produced in a conductor is proportional to its resistance(b) Heat produced in a conductor is proportional to the square of the current(c) Heat produced in a conductor is proportional to charge(d) Heat produced in a conductor is proportional to the time for which current is passed

Which of the following are not reflected by clouds ?

Assertion :   Electric conduction in gases is possible at normal pressure.
Reason     : The electric conduction in gases depends only upon the potential difference between the electrodes.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

An electron in the n = 1 orbit of hydrogen atom is bound by 13.6 eV energy is required to ionize it is(a) 13.6 eV(b) 6.53 eV(c) 5.4 eV   (d) 1.51 eV

Two coherent sources of different intensities send waves which interfere. The ratio of maximum intensity to the minimum intensity is 25. The intensities of the sources are in the ratio(a) 25 : 1(b) 5 : 1(c) 9 : 4(d) 25 : 16

Assertion  :   The temperature coefficient of resistance is positive for metals and negative for p-type semiconductor.
Reason      : The effective charge carriers in metals are negatively charged whereas in p-type semiconductor they are positively charged.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

Assertion :   The capacity of a given conductor remains same even if charge is varied on it.
Reason      : Capacitance depends upon nearly medium as well as size and shape of conductor.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If the assertion and reason both are false.

In a permanent magnet at room temperature.

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.