(a) From the graph of heating curve given below state the melting point and boiling point of the substance.

(b) Complete and rewrite the following nuclear reaction by filling in the blanks.

²³⁵U ⟶ + ₉₀Th + ⁴₂He

Study the below figure and answer the following :

(a) What type of vibration does the figure represent?

(b) State one reason for which the amplitude of the vibration decreases with time.

(c) Write an example of natural vibrations.

A certain beam of α particles, β particles and γ radiations travel through a region of electric field produced between two oppositely charged parallel plates A(+) and B(–).

(a) Which of the above three has the maximum speed?

(b) Which one deviates the most from its original path?

(c) Which one does not deviate at all when passing through a region of electric or magnetic field?

The diagram below shows a vibrating tuning fork E mounted on a sound box X. When the vibrating tuning forks A, B, C and D are placed on the sound box Y one by one, it is observed that a louder sound is produced when the tuning fork B is place on Y.

(a) What is the frequency of tuning fork E?

(b) Why does B produce a louder sound?