Magnetism And Matter — Physics STD 12 Science — Question

An electric dipole placed in a uniform elecrtric field exepriences:

Excitation energy of a hydrogen like ion in its excitation state is 40.8 eV. Energy needed to remove the electron from the ion in ground state is:

The free end of a simple pendulum is attached to the ceiling of a box. The box is taken to a height and the pendulum is oscillated. When the bob is at its lowest point, the box is released to fall freely. As seen from the box during this period, the bob will:

1. Continue its oscillation as before.
2. Stop.
3. Will go in a circular path.
4. Move on a straight line.

The material of wire of potentiometer is(a) Copper(b) Steel(c) Manganin(d) Aluminium

A step up transformer connected to a 220 V AC line is to supply 22 kV for a neon sign in secondary circuit. In primary circuit a fuse wire is connected which is to blow when the current in the secondary circuit exceeds 10 mA. The turn ratio of the transformer is(a) 50(b) 100(c) 150(d)  200

Assertion   :   In practical application, power rating of resistance is not important.
Reason      : Property of resistance remain same even at high temperature.(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.

When light is refracted into a medium:

1. Its wavelength and frequency both increase
2. Its wavelength increases but frequency remains unchanged
3. Its wavelength decreases but frequency remains unchanged.
4. Its wavelength and frequency both decrease.

The zone in a semiconductor diode where no free charge carriers exists is known as the: