Question Detail

Which instrument is used in submarine to see the objects above sea level ?

Pykometer
Polygraph
Photometer
Periscope

Answer: Option D

Explanation:

Pykometer - used to determine the density and coefficient of expansion of liquids,

Polygraph - used to record changes in heartbeat, blood-pressure and respiration,

Photometer - used to compare luminous intensity of the source of light.

1. Atom is the smallest part of matter which takes part in chemical reactions.

True
False

Answer: Option A

2. The rotational effect of a force on a body about an axis of rotation is described in terms of

Centre of gravity
Centripetal force
Centrifugal force
Moment of force

Answer: Option D

3. K. Macmillan invented

Bicycle
Barometer
Calculating Machine
Centigrade Scale

Answer: Option A

Explanation:

K. Macmillan of Scotland invented Bicycle in 1839.

Barometer was invented by E. Torricelli of Italy in 1644.

Calculating Machine was invented by Pascal of France in 1642.

Centigrade Scale was invented by A. Celsius of France in 1742.

4. Force of attraction between the molecules of different substances is called

Surface tension
Cohensive force
Adhesive force
None of above

Answer: Option C

Explanation:

Cohensive force - Force of attraction between the molecules of same substance is called Cohensive force.

5. Which instrument is used to measure changes in volume of substances ?

Dyanamo
Dilatometer
Cyclotron
Electroscope

Answer: Option B

Explanation:

Dyanamo - is used to convert mechanical energy into electrical energy,

Cyclotron - is a charged particle accelerator which can accelerate charged particles to high energies,

Electroscope - is used to detect the presence of an electric charge.