Alternating Current — Physics STD 12 Science — Question

The colour of a star is an indication of its   

(a) Weight

(b) Distance

(c) Surface temperature

(d) Size

Choose the correct statement about the properties of magnetic lines of forces.

Two particles A₁ sand A₂ of masses m₁, m₂ (m₁ > m₂) have the same de-Broglie wavelength. Then:

In Young's interference experiment, the central bright fringe can be identified due to the fact that it:

Fusion processes, like combining two deuterons to form a He nucleus are impossible at ordinary temperatures and pressure. The reasons for this can be traced to the fact:

Electric conduction in a semiconductor takes place due to:

1. Electrons only.
2. Holes only.
3. Both electrons and holes.
4. Neither electrons nor holes.

The ratio of the refractive index of red light to blue light in air is

(a) Less than unity

(b) Equal to unity

(c) Greater than unity

(d) Less as well as greater than unity depending upon the experimental arrangement

Magnetic meridian is:

1. A point.
2. A line along north-south.
3. A horizontal plane.
4. A vertical plane.

The temperature bellow which a material becomes a superconductor is called:

In Young's double slit experiment the intensity of the maxima is I. If the width of each slit is doubled, the intensity of the maxima will be: