The flux linked with the coil at any instant ' t ' is given by $\phi=12 t^2-60 t+275$. The magnitude of induced e.m.f. at $\mathrm{t}=3 \mathrm{~second}$ is
Two sounding sources send waves at certain temperature in air of wavelength 60 cm and 60.6 cm respectively. The frequency of sources differ by 5 Hz . The velocity of sound in air at same temperature is
An ideal gas of mass ' $M$ ' is in the state ' $A$ ' goes to another state B via three different processes. If $Q_1, Q_2$ and $Q_3$ denote the heat absorbed by the gas along the paths 1,2 and 3 respectively, then

The magnitude of magnetic induction at a point on the axis at a large distance ' $r$ ' from the centre of a circular coil of ' $n$ ' turns and area ' $A$ ' carrying current ' I ' is ( $\mu_0=$ permeabilty of free space)