A person is observing a bacteria through a compound microscope. For better observation and to improve its resolving power he should

The inductive reactance of a coil is '$$\mathrm{X}_{\mathrm{L}}$$'. If the inductance of a coil is tripled and frequency of a.c. supply is doubled, then the new inductive reactance will be

In the circuit shown the ratio of quality factor and the bandwidth is

Water flows through a horizontal pipe at a speed '$$\mathrm{V}$$'. Internal diameter of the pipe is '$$\mathrm{d}$$'. If the water is coming out at a speed '$$V_1$$' then the diameter of the nozzle is