Physics - Study Mode

[#401] Planets are
Correct Answer

(B) non-luminous heavenly bodies

Explanation

Solution: Planets are non-luminous heavenly bodies.

[#402] One nanometer is equal to
Correct Answer

(C) 10 -9 m

Explanation

Solution: One nanometer is equal to 10 -9 m.

[#403] Mica is used in electrical appliances such as electric iron because mica is
Correct Answer

(A) a good conductor of heat but a bad conductor of electricity

Explanation

Solution: Mica is used in electrical appliances such as electric iron because mica is a good conductor of heat but a bad conductor of electricity.

[#404] It is easier to roll a barrel full of coal tar than to pull it because
Correct Answer

(B) the rolling friction is much less than the sliding friction

Explanation

Solution: When a body slides (moves with all its surface area in contact) over another body, the resistance faced is due to sliding friction. Hence rolling friction is less than the sliding friction. Thus it is easier to roll a barrel full of coal tar than to pull it.

[#405] Minimum number of unequal vectors which can give zero resultant are
Correct Answer

(B) three

Explanation

Solution: The minimum number of vectors of unequal magnitude required to produce zero resultant is three.