Physics - Study Mode

[#496] When hot liquid is poured into a thick glass tumbler, it cracks because glass :
Correct Answer

(A) Is a bad conductor of heat so only inner surface expands

Explanation

Solution: When hot liquid is poured into a thick glass tumbler, it cracks because glass is a bad conductor of heat so only inner surface expands.

[#497] Mud houses are cooler in summers and warmer in winters as compared to brick houses because
Correct Answer

(B) Mud is a bad conductor

Explanation

Solution: Clay is a poor conductor of heat as compared to wood and bricks. Therefore, clay neither allows the external heat to enter the house in summer nor it allows the internal heat to escape out in winters. Hence, mud houses remain colder in summer and warmer in winter. mud or clay is poor conductor of electricity.

[#498] Why do birds not have respiratory trouble at the time of flying at high altitude ?
Correct Answer

(C) They have extra air sacs

Explanation

Solution: Because flying takes a tremendous amount of energy, birds need to get lots of oxygen. The extra air sacs in their lungs help them to keep fresh air flowing in, unlike mammals, where the “old” air within the trachea and mouth (which has low oxygen content and high CO 2 levels) in inhaled each time. Birds eliminate this “anatomical dead space” problem by using air sacs.

[#499] When a barometer reading suddenly recedes, it indicates that climate–
Correct Answer

(B) Will be extremely stormy

Explanation

Solution: When a barometer reading suddenly recedes, it indicates that climate will be extremely stormy.

[#500] When a barometer is rising air pressure is
Correct Answer

(A) Increasing

Explanation

Solution: When a barometer is rising air pressure is increasing.