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

Domain formation is the necessary feature of:

A metal wire is subjected to a constant potential difference. When the temperature of the metal wire increases, the drift velocity of the electron in it:

In hard X-rays :

The thermal radiation emitted by a body is proportional to Tⁿ where Tis its absolute temperature. The value of n is exactly 4 for:

1. A blackbody.
2. All bodies.
3. Bodies painted black only.
4. Polished bodies only.

The shortest wavelength of X-rays emitted from an X-ray tube depends on the

(a) Current in the tube	(b) Voltage applied to the tube
(c) Nature of gas in the tube	(d) Atomic number of target material

Alnico is used for making permanent magnets because it has:

In a series LCR circuit, resonance occurring at 105Hz. At that time, the potential difference across the 100 resistance is 40V while the potential difference across the pure inductor is 30v. The inductance L of the inductor is equal to.

When current passes through the circuit a compass needle rests in which direction (with respect to the Earth)?

A copper ring is kept horizontal and a bar of magnet is dropped in the direction of the axis of the ring. The acceleration of the falling magnet will be:

Which of the following quantities do not depend on the choice of zero potential or zero potential energy?

1. Potential at a point.
2. Potential difference between two points.
3. Potential energy of a two-charge system.
4. Change in potential energy of a two-charge system.