21- The materials which do not allow heat to pass through them easily are called
(A) Insulators
(B) Conduction
(C) Conductors
(D) None of the above
22- The process by which heat is transferred by movement of a heated fluid such as air or water is known as
(A) Conductors
(B) Convection
(C) Reflection
(D) Insulators
23- The cool air from the sea moves towards the land is called …………. It takes place in night time.
(A) Cold current
(B) Warm current
(C) Sea breeze
(D) Land breeze
24- The cool air from land moves towards sea is called …………………. It takes place in day time
(A) Cold current
(B) Warm current
(C) Sea Breeze
(D) Land breeze
25- Through …………….process the heat of the sun comes to us.
(A) Refraction
(B) Reflection
(C) Convection
(D) Radiation
26- ………..clothes keep us warm during winter and it is poor conductor of heat.
(A) Wool
(B) Cotton
(C) Jute
(D) Synthetic
27-……………..colour objects absorbs more heat than light coloured objects.
(A) Light
(B) Dark
(C) Both A and B
(D) None of the above
28- In solids heat is transferred by……………
(A) Radiation
(B) Convection
(C) Conduction
(D) Both B and C
29- In liquid and gaseous the heat is transferred by ………..
(A) Insulators
(B) Conductors
(C) Radiation
(D) Convection
30- No medium is required for transfer of heat by……………….
(A) Radiation
(B) Convection
(C) Insulators
(D) All of the above
ANSWERS:
21-(A), 22-(B), 23-(C), 24-(D), 25-(D), 26-(A), 27-(B), 28-(C), 29-(D), 30-(A)