Electric Charges and Fields — Physics STD 12 Science — Question

The change in frequency due to Doppler effect does not depend on:

1. The speed of the source.
2. The speed of the observer.
3. The frequency of the source.
4. Separation between the source and the observer.

If a proton is projected in a direction perpendicular to a uniform magnetic field with velocity v and an electron is projected along the lines of force, what will happen to proton and electron(a) The electron will travel along a circle with constant speed and the proton will move along a straight line(b) Proton will move in a circle with constant speed and there will be no effect on the motion of electron(c) There will not be any effect on the motion of electron and proton(d) The electron and proton both will follow the path of a parabola

Which among the following is true about magnetic susceptibility?

When germanium is doped with phosphorus, the doped material has(a) Excess positive charge(b) Excess negative charge(c) More negative current carriers(d) More positive current carriers

A man wearing glasses of focal length +1m cannot clearly see beyond 1m:

1. If he is farsighted.
2. If he is nearsighted.
3. If his vision is normal.
4. In each of these cases.

The thermal conductivity of a rod depends on:

1. Length.
2. Mass.
3. Area of cross section.
4. Material of the rod.

In Fresnel’s biprism experiment, on increasing the prism angle, fringe width will(a) Increase(b) Decrease(c) Remain unchanged(d)  Depend on the position of object