Physics
(i) Define critical angle.
(ii) State one important factor which affects the critical angle of a given medium.
Related Questions
(i) Define couple.
(ii) State the S.I. unit of moment of couple.
(i) Name the physical quantity which is measured in calories.
(ii) How is calorie related to the S.I. unit of that quantity?
An electromagnetic radiation is used for photography in fog.
(i) Identify the radiation.
(ii) Why is this radiation mentioned by you, ideal for this purpose?