Three solenoid coils of same dimensions, same number of turns and same number of layers of windings are taken. Coil 1 has inductance L1 wounded by Mn wire of resistance 6 $$\Omega$$m$$-$$1, coil 2 with inductance L2 wounded by similar wire but in reverse direction in each layer. Coil 3 with inductance L3 wounded by a superconducting wire. The relation between their self inductances will be
A black body radiates energy at the rate E Wm$$-$$2 at high temperature TK. When the temperature is reduced to $$\left( {{T \over 4}} \right)$$ K, the new radiant energy is
The length of the rectangle is l = 15.2 cm and breadth is b = 2.9 cm and the minimum possible measurement by scale = 0.1 cm. Then, the area of the rectangle is (Taking significant figures into consideration)