Current Electri...

A moving coil galvanometer has a resistance of 50 Ω and gives full scale deflection for 10 mA. How could it be converted into an ammeter with a full scaledeflection for 1A

A galvanometer of resistance 25 Ω giving full scale deflection for a current of 10 milliampere, is to be changed into a voltmeter of range 100 V by connecting a resistance of `13.\' in series with galvanometer. Thevalue of resistance R in Ω is

The resistance of a galvanometer is 25 ohm and it requires 50μA for full deflection. The value of the shunt resistance required to convert it into an ammeter of 5 amp is

For comparing the e.m.f.\'s of two cells with a potentiometer, a standard cell is used to develop a potential gradient along the wires. Which of the following possibilities would make the experiment unsuccessful?

In the Wheatstone\'s bridge (shown in figure) X = Y and A > B. The direction of the current between ab will be

A resistance of 4 Ω and a wire of length 5 metres and resistance 5 Ω are joined in series and connected to a cell of e.m.f. 10 V and internal resistance 1 Ω. A parallel combination of two identical cells is balanced across 300 cm of the wire. The e.m.f. E of each cell is

The resistivity of a potentiometer wire is 40 × 10^–8ohm-m and its area of cross-section is 8 × 10^–6m². If 0.2 amp current is flowing through the wire, the potential gradient will be

The resistance of an ideal voltmeter is

Constantan wire is used in making standard resistances because its