National Examinations Board (+2)
+2 Science (Class 11 and 12)
Class 11 · NEB 2076 (old course)
Course Title: Physics (Phy)
Full Marks: 75Pass Marks: 27Time: 3 hrs
Candidates are required to give their answers in their own words as far as practicable. The figures in the margin indicate full marks.
Group A
?(12)
- 1.12
Answer in brief, any six questions. a. The energy of a photon is given by . Find the dimension and unit of Plank's constant , where is the frequency of radiation. [2] b. From a flying aeroplane a body should be dropped in advance to hit the target, why? [2] c. A light body and a heavy body have the same momentum. Which one will have greater Kinetic energy? Explain. [2] d. A person sitting in an artificial satellite of the earth feels weightlessness, but a person standing on moon has weight through the moon is a satellite of the earth. Why? [2] e. The passengers in a small boat are not allowed to stand, why? [2] f. If the ice on the polar caps of the earth melts, how will it affect the duration of the day? Explain. [2] g. Why does hot soup taste better than cold soup? [2]
- 2.4
Answer in brief, any two questions. a. The latent heat of vaporization is much larger than the latent heat of fusion of a substance. Why? [2] b. Why does it take longer time to dry wet clothes in rainy summer than in sunny winter? [2] c. The internal energy of a compressed gas is less than that of a rarefied gas at the same temperature. Why? [2]
- 3.2
Answer in brief, any one question. a. The sun is less bright in morning and evening as compared to that at noon although its distance from the observer is almost the same. Why? [2] b. When white light is dispersed by a prism, red light appears at the top of the spectrum where as violet at the bottom. Why? [2]
- 4.2
Answer in brief, any one question. a. Bits of paper are attracted to an electrified comb, even though they have no net charge. How is this possible? [2] b. Can two electric lines of force intersect each other? Explain. [2] GROUP: B | B | 12
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