Electromagnetic Waves — Physics STD 12 Science — Question

The positive terminal of 12V battery is connected to the ground. Then the negative terminal will be at:

A charged particle in a plasma trapped in a magnetic bottle leaks out after a millisecond. What is the total work done by the magnetic field during the time the particle is trapped?

Assertion  : If the temperature of a semiconductor is increased then it's resistance decreases.
Reason      : The energy gap between conduction band and valence band is very small(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.

The term on the RHS of the Gauss’s law shows the:

X-ray incident on a material:

Given a current carrying wire of non-uniform cross-section. Which one of the following is constant through out the length of wire ?

The potential gradient at which the dielectric of a condenser just gets punctured is called:

Mark the correct statements:

1. The nuclear force between two protons is always greater than the electromagnetic force between them.
2. The electromagnetic force between two protons is always greater than the gravitational force between them.
3. The gravitational force between two protons may be greater than the nuclear force between them.
4. Electromagnetic force between two protons may be greater than the nuclear force acting between them.