Current Electricity — Physics STD 12 Science — Question

Two coherent light sources S₁ and S₂ (l= 6000 Å) are 1mm apart from each other. The screen is placed at a distance of 25 cm from the sources. The width of the fringes on the screen should be

(a) 0.015 cm

(b) 0.025 cm

(c) 0.010 cm

(d) 0.030 cm

The unit of magnetic moment is

(a) Wb/m

(b)

(c) A.m

(d)

A body moving towards a finite body at rest collides with it. It is possible that:

1. Both the bodies come to rest.
2. Both the bodies move after collision.
3. The moving body comes to rest and the stationary body starts moving.
4. The stationary body remains stationary, the moving body changes its velocity.

What type of surface is the surface of a conductor?

In the equation AB = C, A is the current density, C is the electric field, Then B is:

Three identical point charges, as shown are placed at the vertices of an isosceles right angled triangle. Which of the numbered vectors coincides in direction with the electric field at the mid-point M of the hypotenuse

(a) 1

(b) 2

(c) 3

(d) 4

The electrical conductivity of pure germanium can be increased by:

1. Increasing the temperature.
2. Doping acceptor impurities.
3. Doping donor impurities.
4. Irradiating ultraviolet light on it.

A semi conductor device with both active and passive electronic elements diffused into a silicon water to form a functional circuit is called.

The pressure of a gas kept in an isothermal container is 200kPa. If half the gas is removed from it, the pressure will be:

1. 100kPa.
2. 200kPa.
3. 400kPa.
4. 800kPa.