Electric Charges and Fields — Physics STD 12 Science — Question

The switches in figure are closed at t = 0 and reopened after a long time at t = t₀:

Which of the following pairs has quantities of the same dimensions?

1. Magnetic field B and magnetizing field intensity H.
2. Magnetic field B and intensity of magnetization I.
3. Magnetizing field intensity H and intensity of magnetization I.
4. Longitudinal strain and magnetic susceptibility.

If a capacitor is connected to two different A.C. generators, then the value of capacitive reactance is:

Two light beams superimposed each other constructively this results in:

How does the red shift confirms that the universe is expanding

(a) Due to Wien's law	(b) Due to Stefan's law
(c) Due to Kirchhoff's law	(d) Due to Doppler's effect

Light is a form of _______ that we can detect with our ________ .

If a transparent medium of refractive index m = 1.5 and thickness t = 2.5 × 10^–5 m is inserted in front of one of the slits of Young’s Double Slit experiment, how much will be the shift in the interference pattern? The distance between the slits is 0.5 mm and that between slits and screen is 100 cm

(a) 5 cm

(b) 2.5 cm

(c) 0.25 cm

(d) 0.1 cm

The resistivity of iron is 1 . The resistance of a iron wire of particular length and thickness is 1 ohm. If the length and the diameter of wire both are doubled, then the resistivity in ohm - m  will be

(a)

(b) 2

(c) 4

(d) 8

The mass of a substance liberated when a charge ‘q’ flows through an electrolyte is proportional to

(a) q

(b) 1/q

(c)

(d) 1/

Half life of a radio-active substance is 20 minutes. The time between 20% and 80% decay will be

(a) 20 minutes

(b) 40 minutes

(c) 30 minutes

(d) 25 minutes