Electrostatics — Physics STD 12 Science — Question

In a Wheatstone’s bridge all the four arms have equal resistance R.  If the resistance of the galvanometer arm is also R, the equivalent resistance of the combination as seen by the battery is

(a)

(b) R

(c) 2R

(d)

On increasing the intensity of incident light on a metal surface :

A capacitor with no dielectric is connected to a battery at t = 0. Consider a point A in the connecting wires and a point B in between the plates.

1. There is no current through A.
2. There is no current through B.
3. There is a current through A as long as the charging is not complete.
4. There is a current through B as long as the charging is not complete.

A ray of light passes through an equilateral glass prism in such a manner that the angle of incidence is equal to the angle of emergence and each of these angles is equal to 3/4 of the angle of the prism. The angle of deviation is

(a) 45°

(b) 39°

(c) 20°

(d) 30°

We combined a convex lens of focal length f₁ and concave lens of focal lengths f₂ and their combined focal length was F.  The combination of these lenses will behave like a concave lens, if

(a) f1 > f2

(b) f1 < f2

(c) f1 = f2

(d) f1 ≤ f2

In Young's double slit experiment, the interference pattern obtained with white light will be:

X-ray from a Coolidge tube is incident on a thin aluminium foil. The intensity of the X-ray transmitted by the foil is found to be I₀. The heating current is increased to increase the temperature of the filament. The intensity of the X-ray transmitted by the foil will be:

1. zero
2. < I₀
3. I₀
4. > I₀

In an atom, electrons revolve around the nucleus. This gives rise to:

The ratio of momenta of an electron and an α- particle which are accelerated from rest by a potential difference of 100 V is

(a) 1

(b)

(c)

(d)