Magnetism and Matter — Physics STD 12 Science — Question

The coefficient of mutual induction between two coils is 4H. If the current in the primary reduces from 5A to zero in 10^-3 second then the induced emf in the secondary coil will be

Which line shows the path of beta radiation in a magnetic field?

The cellular mobile radio frequency band is:

A radioactive sample has  active atoms at t = 0. If the rate of disintegration at any time is R and the number of atoms is N, then the ratio R/N varies with time as

(a)

(b)

(c)

(d)

Soap bubble appears coloured due to the phenomenon of

(a) Interference

(b) Diffraction

(c) Dispersion

(d) Reflection

The electric intensity  E, current density j  and specific resistance k are related to each other by the relation

(a) E = j/k

(b) E = jk

(c) E = k/j

(d) k = jE

When white light passes through the achromatic combination of prisms, then what is observed

(a) Only deviation	(b) Only dispersion
(c) Deviation and dispersion	(d) None of the above

A circular loop carrying a current is replaced by ann equivalent magnetic dipole. A point on the axis of the loop is in:

Speed of electromagnetic waves is the same:

The capacitance between the points A and B in the given circuit will be

(a) 1 μF

(b) 2 μF

(c) 3 μF

(d) 4 μF