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

When a forward bias is applied to a p-n junction, it

1. Raises the potential barrier.
2. Reduces the majority carrier current to zero.
3. Lowers the potential barrier.
4. None of the above.

What is the average friction force when a person has a usual 1km walk?

The work function of a substance depends on which factor?

An equi-convex lens has refractive index 1.5. Write its focal length in terms of radius of curvature R.

We often say, "A current is going through the wire." What goes through the wire, the charge or the current?

Two wires of equal length, one of copper and the other of manganin have the same resistance. Which wire is thicker?

To measure the magnetic moment of a bar magnet, one may use:

An electric lamp and a candle produce equal illuminance at a photometer screen when they are placed at 80cm and 20cm from the screen respectively. The lamp is now covered with a thin paper which transmits 49% of the luminous flux. By what distance should the lamp be moved to balance the intensities at the screen again?

When the skeleton of an elephant and the skeleton of a mouse are prepared in the same size, the bones of the elephant are shown thicker than those of the mouse. Explain why the bones of an elephant are thicker than proportionate. The bones are expected to withstand the stress due to the weight of the animal.