Current Electri...

A potentiometer wire of length $$10 m$$ is connected in series with a battery. The e.m.f. of a cell balances against $$250 cm$$ length of wire. If length of potentiometer wire is increased by $$1 m$$, the new balancing length of wire will be

Figure below shows a portion of an electric circuit with the currents in amperes and their directions. The magnitude and direction of the current in the portion $$PQ$$ is

The best instrument for accurate measurement of emf of a cell.

Two resistors $$400\ \Omega $$ and $$800\ \Omega$$ are connected in series with a 6 V battery. the potential difference measured by voltmeter across $$400\ \Omega $$ resistor is:

A voltmeter having a resistance of $$998\Omega$$ is connected to a cell of emf $$2$$V and internal resistance $$2\Omega$$. The error in the measurement of emf will be.

A potentiometer is an ideal device of measuring potential difference because

The ratio of resistance of two copper wire of the same length and of same cross-sectional area, when connected in series to that when connected in parallel, is

Pick out the wrong feature about carbon resistors

Kirchhoff's first law ie, $$\displaystyle \Sigma i=0$$ at a junction is based on the law of conservation of

The diagram shows identical lamps X and connected in series with a battery. The lamps light with normal brightness.If a third lamp Z is connected in parallel with lamp X, then what will happens to the brightness of the lamp Y?