# Physics Top MCQs – 2

Food is cooked in a pressure cooker quickly because
(A) Boiling point of water decreases
(B) Boiling point of water increases
(C) It absorbs heat quickly
(D) It retains heat for a longer duration
A glass tumbler containing ice shows droplets of water on the outer surface because
(A) The outer surface of the tumbler shows hygroscopic effect
(B) The moisture in the air on coming in contact with the cold surface of the tumbler condenses in the form of droplets of water
(C) Water from inside oozes out through minute porous wall of the tumbler
(D) Both (A) and (C)

The sky appears blue because
(A) It is actually blue
(B) The atmosphere scatters blue light more than the others
(C) All colours interface to produce blue
(D) In white light, blue colour dominates

A thick glass tumbler cracks more easily than a thin one when hot water is poured into it. Why? (A) Thick glass is more brittle than thin glass.
(B) Thick glass is of inferior quality.
(C) The inner surface of the tumbler expands more than its outer surface.
(D) The outer surface of the tumbler expands more than its inner surface.

Let a thin capillary tube be replaced with another tube of insufficient length then, we find water
(A) Will overflow
(B) Will not rise
(C) Depressed
(D) Change its meniscus

Rectifiers are used to convert
(A) Direct current to Alternating current
(B) Alternating current to Direct current
(C) High voltage to low voltage
(D) Low voltage to high voltage

Magnetism at the centre of a bar magnet is
(A) Minimum
(B) Maximum
(C) Zero
(D) Minimum or maximum

Point A is at a lower electrical potential than point B. An electron between them on the line joining them will
(A) Move towards A
(B) Move towards B
(C) Move at right angles to the line joining A and B
(D) Remain at rest

It takes much longer to cook food in the hills than in the plains, because
(A) In the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100°C causing an increase in cooking time
(B) Due to low atmospheric pressure on the hills, the water boils at a temperature higher than 100°C and therefore water takes longer to boil
(C) In the hills the atmospheric density is low and therefore a lot of heat is lost to the atmosphere
(D) In the hills the humidity is high and therefore a lot of heat is absorbed by the atmosphere leaving very little heat for cooking