Question 2.
(a) What do you understand by refraction of Might?
[2]
(b) What are isobars? Give one example or isobars.
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(c) Define one kilo-calorie of heat.
[2]
(di Define couple. State the S.L. unit of moment of couple.
[2]
(e) State the conditions required for that internal reflection of light to take place, [2]
Answers
Explanation:
a) Refraction is the bending of light as it passes from one substance to another. Here the light ray passes from air to glass and back to air. The bending is caused by the differences in density between the two substance.
b)The atoms that have same number of nucleons. Isobars of different chemical elements have different atomic number but have the same mass number. example:-Argon (18Ar40)
c)One kilo-calorie is the amount of heat required to raise the temperature of one kilogram of water by 1 °C.
d) Two equal and opposite forces acting prependicular and separated by some distance d is called couple.SI unit : N m
e)1) Light must travel from a denser medium to a rarer medium.
2) The angle of incidence must be greater than the critical angle for the pair of media.