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

A cubical box of volume 216cm³ is made up of 0.1cm thick wood. The inside is heated electrically by a 100W heater. It is found that the temperature difference between the inside and the outside surface is 5^°C in steady state. Assuming that the entire electrical energy spent appears as heat, find the thermal conductivity of the material of the box.

Which wavelengths will be emitted by a sample of atomic hydrogen gas (in ground state) if electrons of energy 12.2eV collide with the atoms of the gas?

Name the following constituent radiations of electromagnetic spectrum which

1. produce intense heating effect.
2. is absorbed by the ozone layer in the atmosphere.
3. is used for studying crystal structure.

Write one more application forr each of these radiations.

Explain the phenomenon of nuclear fission.

Which is easier to remove: orbital electron from an atom or a nucleon from a nucleus?

A ball is dropped from a balloon going up at a speed of 7m/s. If the balloon was at a height 60m at the time of dropping the ball, how long will the ball take in reaching the ground?

A charge Q is distributed uniformly over a metallic sphere of radius R. Obtain the expressions for the electric field (E) and electric potential (V) at a point 0 < x < R.
Show on a plot the variation of E and V with x for 0 < x < 2R.

The ends of a metre stick a.re maintained at 100^°C and 0^°C. One end of a rod is maintained at 25^°C. Where should its other end be touched on the metre stick so that there is no heat current in the rod in steady state?

Calculate the current drawn from the battery in the given network shown here. State Kirchhoff’s loop law and name the law on which it is based.