A room heater is rated $400 \mathrm{~W}, 220 \mathrm{~V}$. If the supply voltage drops to 200 V , what will be the power consumed (approximately)?

A 100-turn closely wound circular coil of radius 5 cm has a magnetic field of $3.14 \times 10^{-3} \mathrm{~T}$ at its centre. The current flowing through the coil, and the magnitude of the magnetic moment of this coil are, respectively :

(Take $\mu_0=4 \pi \times 10^{-7} \mathrm{~T} \mathrm{~m} / \mathrm{A}$ )

A rectangular wire loop of sides 8 cm and 3 cm with a small cut, is moving out of a region of uniform magnetic field of magnitude 0.3 T directed normal to the plane of the loop. The emf developed across the cut, if the velocity of the loop is $2 \mathrm{~cm} \mathrm{~s}^{-1}$, in a direction normal to the shorter side of the loop, will be :

Four statements are given ( $A$ is mass number):

A. The volume of a nucleus is proportional to $A^{1 / 3}$.

B. The volume of a nucleus is proportional to $A$.

C. The difference in mass of an atom and its nucleus is called the mass defect.

D. The difference in mass of a nucleus and its constituents is called the mass defect.

Choose the correct answer from the options given below: