Physics Top MCQs – 7

Mica is used in electrical appliances such as electric iron because mica is
(A) A good conductor of heat but a bad conductor of electricity
(B) A bad conductor of heat but a good conductor of electricity
(C) A good conductor of heat as well as electricity
(D) A bad conductor of heat as well as electricity
Answer: Option A

The ‘pulse’ of the aquatic environment can be ascertained by measuring
(A) Nitrogen
(B) Oxygen
(C) Alkalinity
(D) Conductivity
Answer: Option B
What is the function of a dynamo?
(A) To convert heat energy into light energy
(B) To convert light energy into heat energy
(C) To convert mechanical energy into electrical energy
(D) To convert electrical energy into mechanical energy
Answer: Option C

To produce sound it is necessary that
(A) The source should execute longitudinal vibrations
(B) The source should execute transverse vibrations
(C) The source may execute any type of vibrations
(D) The vibrations of source are not necessary
Answer: Option C

Friction can be reduced by changing from
(A) Sliding to rolling
(B) Rolling to sliding
(C) Potential energy to kinetic energy
(D) Dynamic to static
Answer: Option A

If the plane of the earth’s equator were not inclined to the plane of the earth’s orbit
(A) The year would be longer
(B) The winters would be longer
(C) There would be no change of seasons
(D) The summers would be warmer
Answer: Option C

Change of seasons occur due to
I. Earth’s rotation II. Earth’s revolution
III. Inclination of Earth’s axis
(A) I and II only
(B) II and III only
(C) I and III only
(D) I, II and III
Answer: Option B

When a ship crosses the International Date Line from West to East
(A) It losses one day
(B) It gains one day
(C) It loses half a day
(D) It gains half a day
Answer: Option A

A lunar eclipse occurs when
(A) Sun, Moon and Earth are not in the same line
(B) Earth comes between the Sun and the Moon
(C) Moon comes between the Sun and the Earth
(D) Sun comes between the Earth and the Moon
Answer: Option B

“Equinox” means
(A) Days are longer than nights
(B) Days and nights are equal
(C) Days are shorter than nights
(D) None of these
Answer: Option B