Current Electricity — Physics STD 12 Science — Question

Planck constant has the same dimensions as:

1. Force × time.
2. Force × distance.
3. Force × speed.
4. Force × distance × time.

A square loop of side 22 cm is converted into circular loop of 0.45. If uniform magnetic field of 0.2 T is perpendicular to the loop, then induced electromotive force in the loop is:

In semiconductors, at a room temperature:

When a piece of aluminium wire of finite length is drawn through a series of dies to reduce its diameter to half its original value, its resistance will become(a) Two times(b) Four times(c) Eight times(d) Sixteen times

If a ray of light goes from a rarer medium to a denser medium, will it bend towards the normal or away from it?

Which of the following parameters are the same for all hydrogen-like atoms and ions in their ground states?

A watch glass containing some powdered substance is placed between the pole pieces of a magnet. Deep concavity is observed at the centre. The substance in the watch glass is:

How can we explain the reddish appearance of sun at sunrise or sunset? 

The capacitance of the capacitor is directly proportional to the: