In series $$L C R$$ circuit at resonance, the phase difference between voltage and current is
An ideal transformer has a turns ratio of 10. When the primary is connected to $$220 \mathrm{~V}, 50 \mathrm{~Hz}$$ as source, the power output is
The current in a coil changes from $$2 \mathrm{~A}$$ to $$5 \mathrm{~A}$$ in $$0.3 \mathrm{~s}$$. The magnitude of emf induced in the coil is $$1.0 \mathrm{~V}$$. The value of self-inductance of the coil is
A metallic rod of length $$1 \mathrm{~m}$$ held along east-west direction is allowed to fall down freely. Given horizontal component of earth's magnetic field $$B_H=3 \times 10^{-5} \mathrm{~T}$$. the emf induced in the rod at an instant $$t=2 \mathrm{~s}$$ after it is released is
(Take, $$g=10 \mathrm{~ms}^{-2}$$ )