Alternating Current — Physics STD 12 Science — Question

When a dielectric slab is introduced between the two plates of condenser then its capacity ___________.

The electric field at a point on equatorial line of a dipole and direction of the dipole moment:

Charges of + 10 Coulombs are placed at both corners of one diagonal of a square and charges of -10 coulomb are placed at the other two corners, then at the centre of the square:

A common emitter amplifier is designed with NPN transistor (a = 0.99). The input impedance is 1 KW and load is 10 KW. The voltage gain will be(a) 9.9(b) 99(c) 990(d) 9900

Which of the following are conservative forces:

A thick plane mirror shows a number of images of the filament of an electric bulb. Of these, the brightest image is the(a) First(b) Second(c) Fourth(d) Last

A solid sphere falls with a terminal velocity of 20m/s in air. If it is allowed to fall in vacuum,

1. Terminal velocity will be 20m/s
2. Terminal velocity will be less than 20m/s
3. Terminal velocity will be more than 20m/s
4. There will be no terminal velocity.

What happens to the wavelength of a photon after it collides with an electron?

In a  PN-junction diode (a) The current in the reverse biased condition is generally very small(b) The current in the reverse biased condition is small but the forward biased current is independent of the bias voltage (c) The reverse biased current is strongly dependent on the applied bias voltage(d) The forward biased current is very small in comparison to reverse biased current

In intrinsic semiconductor at room temperature, number of electrons and holes are (a) Unequal(b) Equal(c) Infinite(d) Zero