Moving Charges and Magnetism — Physics STD 12 Science — Question

Two identical induction coils each of inductance L joined in series are placed very close to each other such that the winding direction of one is exactly opposite to that of the other, what is the net inductance

(a) L2

(b) 2L

(c) L/2

(d) Zero

Flux density under trailing pole tips in case of generator will:

Which law can ampere’s circuital be derived from?

If a magnetic substance is kept in a magnetic field, then which of the following is thrown out

(a) Paramagnetic

(b) Ferromagnetic

(c) Diamagnetic

(d) Antiferromagnetic

In what form is energy present in the capacitor?

Five lumen/watt is the luminous efficiency of a lamp and its luminous intensity is 35 candela. The power of the lamp is

(a) 80 W

(b) 176 W

(c) 88 W

(d) 36 W

The spectral series of the hydrogen spectrum that lies in the ultraviolet region is the

(a) Balmer series

(b) Pfund series

(c) Paschen series

(d) Lyman series

Which of the following has its permeability less than that of free space?

Assertion  : The electromagnetic waves of shorter wavelength can travel longer distances on earth's surface than those of longer wavelengths.

Reason      :  Shorter the wavelength, the larger is the velocity of wave propagation.

(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.

The equation →∑e = ∑IR is applicable to which law?