The resistance of each arm of the Wheatstone's bridge is 10 ohm. A resistance of 10 ohm is connected in series with a galvanometer then the equivalent resistance across the battery will be

The potentiometer is best for measuring voltage, as

Two bulbs of (40 W, 200 V), and (100 W, 200 V). Then correct relation for their resistances

A car battery of emf 12 V and internal resistance $$5 \times {10^{ - 2}}$$ $$\Omega $$., receives a current of 60 amp, from external source, then terminal potential difference of battery is