Semiconductor Electronics: Materials, Devices and Simple Circuits — Physics STD 12 Science — Question

Solve the previous question if the closed loop is completely enclosed in the circuit containing the switch.

1. An anticlockwise current-pulse.
2. A clockwise current-pulse.
3. An anticlockwise current-pulse and then a clockwise current-pulse.
4. A clockwise current-pulse and then an anticlockwise current-pulse.

When stopping potential is applied in an experiment on photoelectric effect, no photocurrent is observed. This means that:

Mark the correct options:

1. Gauss's law is valid only for symmetrical charge distributions.
2. Gauss's law is valid only for charges placed in vacuum.
3. The electric field calculated by Gauss's law is the field due to the charges inside the Gaussian surface.
4. The flux of the electric field through a closed surface due to all the charges is equal to the flux due to the charges enclosed by the surface.

Identify the type of materials which develop electric currents in them, when an electric field is applied.

An object may have:

1. Varying speed without having varying velocity.
2. Varying velocity without having varying speed.
3. Nonzero acceleration without having varying velocity.
4. Nonzero acceleration without having varying speed.

The energy emitted by a source is in the form of:

Assertion  : The positively charged nucleus of an atom has a radius of almost .

Reason      : In a-particle scattering experiment, the distance of closest approach for a-particles is

(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c) If assertion is true but reason is false.

(d) If the assertion and reason both are false.

Two charges are placed at certain distance apart. A metallic sheet is placed between them. What will happen to the force between the charges?

The north pole of a long horizontal bar magnet is being brought closer to a vertical conducting plane along the perpendicular direction. The direction of the induced current in the conducting plane will be

(a) Horizontal

(b) Vertical

(c) Clockwise

(d) Anticlockwise

In the above question, the resistance between the square faces is

(a) 3

(b) 3

(c) 3

(d) 3