Refraction of Light at Plane Surfaces — Physics STD 10 — Question

(a) Which of the following quality determines the loudness of a sound wave?
(i) wavelength (ii) frequency and (iii) amplitude
(b) How is loudness related to the quantity mentioned above in part(a)?

Out of the two lenses one concave and the other convex state which is a convergent or a divergent type of a lens. Give a reason for your answer.

How are critical angles related to the refractive index of the medium?

Draw a simplified labelled diagram of a hot cathode ray tube.

Name the waves used for sound ranging. State one reason for their use.

A bucket contains 10 liters of water at 80°C. Cold water at 25°C is run from a tap into the bucket of hot water for 20 seconds and the temp. Of the water in the bucket falls to 50°C.
(a) Calculate the rate at which cold water came out of the tap.
(b) State an assumption made in the above calculation.

State the principle of a D. C. motor.

Make the correct choices in the following items :
A lens used as a magnifying glass
(i) ls a diverging lens
(ii) Produces a virtual image
(iii) ls placed with the object nearer the lens than the principle focus

Explain the difference between a uniform linear motion and a uniform circular motion.

(a) What are
(i) beta particles, (ii) gamma radiations?
(b) Explain briefly what changes take place within the nuclei, when beta particle is emitted by a radioactive substance.