Current Electri...

A voltmeter has a range 0–V with a series resistance R. With a series resistance 2R, the range is 0–V\'. Thecorrect relation between V and V\' is

The measurement of voltmeter in the following circuitis

If an ammeter is to be used in place of a voltmeter then we must connect with the ammeter a

A 10 m long wire of 20 Ω resistance is connected with a battery of 3 volt e.m.f. (negligible internal resistance) and a 10 Ω resistance is joined to it is series. Potential gradient along wire in volt per meter is

A potentiometer has uniform potential gradient across it. Two cells connected in series (i) to support each other and (ii) to oppose each other are balanced over 6 m and 2 m respectively on the potentiometer wire. The e.m.f.\'s of the cells are in the ratio of

The material of wire of potentiometer is

To convert a 800 mV range milli voltmeter of resistance 40 Ω into a galvanometer of 100 mA range, the resistance to be connected as shunt is

The potential difference across the 100 Ω resistance in the following circuit is measured by a voltmeter of 900 Ω resistance. The percentage error made in readingthe potential difference is

A galvanometer, having a resistance of 50 Ω gives a full scale deflection for a current of 0.05 A. The length in meter of a resistance wire of area of cross-section 2.97 × 10^–2cm² that can be used to convert the galvanometer into an ammeter which can read a maximum of 5 A current is (Specific resistance of the wire = 5 × 10^–7 m Ω)

Resistance of 100 cm long potentiometer wire is 10 Ω, it is connected to a battery (2 volt) and a resistance R in series. A source of 10 mV gives null point at 40 cmlength, then external resistance R is