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

A large virtual image of object is formed by :

The rest mass of the photon is (a) 0(b) ∞(c) Between 0 and ∞(d) Equal to that of an electron

If the frequency of EM radiations is halved then the energy of EM radiation will become:

When light propagates in vacuum there is an electric field and a magnetic field. These fields:

1. Are constant in time.
2. Have zero average value.
3. Are perpendicular to the direction of propagation of light.
4. Are mutually perpendicular.

Assertion  :   The temperature coefficient of resistance is positive for metals and negative for p-type semiconductor.
Reason      : The effective charge carriers in metals are negatively charged whereas in p-type semiconductor they are positively charged.(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.

A proton beam is going from north to south and an electron beam is going from south to north. Neglecting the earth's magnetic field, the electron beam will be deflected

1. Towards the proton beam.
2. Away from the proton beam.
3. Upwards.
4. Downwards.

A convex lens of ______ focal length gives a greater magnification than lenses of _______ focal length.

In Young's double slit interference experiment, the slit separation is made 3 fold. The fringe width becomes(a) 1/3 times(b) 1/9 times(c) 3 times(d) 9 times

A capacitor of capacity C has charge Q  and stored energy is W. If the charge is increased to 2Q, the stored energy will be(a) 2W(b) W/2(c) 4W(d) W/4

The velocity of emitted electrons in photelectric effect depends :