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

Electric lines of force about a negative point charge are:

The reactance of a circuit is zero. It is possible that the circuit contains:

1. An inductor and a capacitor.
2. An inductor but no capacitor.
3. A capacitor but no inductor.
4. Neither an inductor nor a capacitor.

A sphere of radius R has a uniform distribution of electric charge in its volume. At a distance x from its centre, for x < R, the electric field is directly proportional to

(a)

(b)

(c) x

(d)

The work function of a metal is

(a) The energy for the electron to enter into the metal

(b) The energy for producing X-ray

(c) The energy for the electron to come out from metal surface

(d) None of these

A ray passes through a prism of angle 60° in minimum deviation position and suffers a deviation of 30°. What is the angle of incidence on the prism

(a) 30°

(b) 45°

(c) 60°

(d) 90°

The ability of an optical instruments to show the images of two adjacent point objects as separate is called:

Which one of the following has the identical property for isotopes?

Equal potentials are applied on an iron and copper wire of same length.  In order to have the same current flow in the two wires, the ratio r (iron)/r (copper) of their radii must be (Given that specific resistance of iron =  ohm–m and specific resistance of copper =  1.7  ohm-m)

(a) About 1.2

(b) About 2.4

(c) About 3.6

(d) About 4.8

Cutoff wavelength of X-rays coming from a Coolidge tube depends on the:

1. Target material.
2. Acelerating voltage.
3. Separation between the target and the filament.
4. Temperature of the filament.