131) Fish plates are used in railway tracks
(A) To avoid tracks being distorted due to temperature fluctuation
(B) To control the speed of the train
(C) To connect two rails
(D) To keep the rails equidistant
132) Food is cooked quickly in a pressure cooker because
(A) Boiling point of water is decreased
(B) Boiling point of water is increased
(C) It absorbs heat quickly
(D) It retains heel for a long duration
133) In an earthen pot cooling of water depends upon
(A) Outside temperature
(B) Atmospheric humidity
(C) Wind
(D) All of the above
134) A fuse wire is used to
(A) To make the electrical circuit strong
(B) Convert AC Into DC
(C) Convert DC Into AC
(D) Prevent an unduly high electric current to pass through a circuit
135) A molecule is
(A) A class of organic compounds
(B) The smallest unit of a substance that retains the properties of the substance
(C) The spectrum of a substance
(D) A small mass
136) The nucleus of atom consists of
(A) Protons + Electrons
(B) Only proton
(C) Proton + Neutron + Electron
(D) Protons and Neutrons
137) Four identical kettles with the same amount of water, have bases made of different metals of the same thickness, If these are placed on identical flames water will boil first in the kettle with a base made of
(A) Brass
(B) Copper
(C) Aluminium
(D) Steel
138) Sound travels with a different speed in different media. In what order does the velocity of sound increase in these media?
(A) Water, iron and air
(B) Iron, air and water
(C) Air, water and iron
(D) Iron, water and air
139) In electric fittings, the wires are earthed because
(A) In case of a short circuit, current passes to the earth
(B) It avoids leakage of electricity
(C) It completes the electric circuit
(D) It reduces fluctuation
140) Which of the following metals is used in aircraft?
(A) Chromium
(B) Titanium
(C) Palladium
(D) None of these