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

Two sources of waves are called coherent if

(a) Both have the same amplitude of vibrations

(b) Both produce waves of the same wavelength

(c) Both produce waves of the same wavelength having constant phase difference

(d) Both produce waves having the same velocity

At a place, if the earth's horizontal and vertical components of magnetic fields are equal, then the angle of dip will be

(a) 30°

(b)  90°

(c) 45°

(d)  0°

Two negative charges are kept at a certain distance in the air medium. What will happen if a dielectric slab is inserted between them?

The rest mass of an electron as well as that of positron is 0.51 MeV. When an electron and positron are annihilate, they produce gamma-rays of wavelength(s)

(a) 0.012 Å

(b) 0.024 Å

(c) 0.012 Å to ¥

(d) 0.024 Å to ¥

On decreasing the distance between the plates of a parallel plate capacitor, its capacitance:

Orbital acceleration of electron is

(a)

(b)

(c)

(d)

Your are given three equal resistances. In how many combinations can they be arranged?

The diffraction effect can be observed in

When two identical capacitors are in series have 3mF  capacitance and when parallel 12mF. What is the capacitance of each

(a) 6 μF

(b) 3 μF

(c) 12 μF

(d) 9 μF

Mark the correct options:

1. Gauss's law is valid only for symmetrical charge distributions.
2. Gauss's law is valid only for charges placed in vacuum.
3. The electric field calculated by Gauss's law is the field due to the charges inside the Gaussian surface.
4. The flux of the electric field through a closed surface due to all the charges is equal to the flux due to the charges enclosed by the surface.