Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

In Young's double slit experiment, the phase difference between the light waves reaching third bright fringe from the central fringe will be (λ =6000 Å )

(a) Zero

(b) 2π

(c) 4 π

(d) 6 π

A crystal diode is a

(a) Non-linear device

(b) Amplifying device

(c) Linear device

(d) Fluctuating device

The phase difference between alternating emf and current in a purely capacitive circuit will be.

A 500 Hz modulating voltage fed into an FM generator produces a frequency deviation of 2.25 kHz. If amplitude of the voltage is kept constant but frequency is raised to 6 kHz then the new deviation will be

(a) 4.5 kHz

(b) 54 kHz

(c) 27 kHz

(d) 15 kHz

64 small drops of mercury, each of radius r and charge q coalesce to form a big drop. The ratio of the surface density of charge of each small drop with that of the big drop is

(a) 1 : 64

(b) 64 : 1

(c) 4 : 1

(d) 1 : 4

Which scientist proposed the concept of atomic mass?

In Thomson's experiment to measure e/ m of electron, the electric and the magnetic fields are.

The time taken by a photo-electron to come out after the photon strikes is approximately:

An electron having a charge e moves with a velocity v in X-direction. An electric field acts on it in Y-direction? The force on the electron acts in:

A conducting gas is in the form of a long cylinder. Current flows through the gas along the length of the cylinder. The current is distributed uniformly across the cross-section of the gas. Disregard thermal and electrostatic forces among the gas molecules. Due to the magnetic fields set up inside the gas and the forces which they exert on the moving ions, the gas will tend to: