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?

(a) Name two factors on which the force experienced by a conductor carrying current, placed in a magnetic field, depends. Also, state how these factors affect the force.

(b) With the help of which rule you can determine the direction of force acting on a current carrying conductor placed in a magnetic field?

(a) What is nuclear energy?

(b) After emission of a nuclear radiation, the atomic number of the daughter nucleus increases by 1. Identify the nuclear radiation.

(c) Write a nuclear reaction indicating the nuclear change mentioned in (b).

(d) What is the special name given to the parent and daughter nucleus when this radiation is emitted?

(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