Consider matrix $$A = \left[ {\matrix{ 2 & 1 \cr 1 & 2 \cr } } \right]$$, if $${A^{ - 1}} = \alpha I + \beta A$$, where $$\alpha$$, $$\beta$$ $$ \notin $$ R, then ($$\alpha$$ + $$\beta$$) is equal to (where A$$-$$1 denotes the inverse of matrix A)
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