Current Electricity and Electrical Instrument Questions

The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 Ω is

Two cells, each of e.m.f. E and internal resistance r, are connected in parallel across a resistor R. The power dissipated in the resistor is maximum if :-

In a network as shown in the figure the potential difference across the resistance 2R is (the cell has an emf of E and has no internal resistance) :...

Across a metallic conductor of non-uniform cross section a constant potential difference is applied. The quantity which remains constant along the conductor is :

A potentiometer wire has length 4 m and resistance 8Ω The resistance that must be connected in series with the wire and an accumulator of e.m.f. 2V, so as to get a potential gradient 1 mV per cm ...

A, B and C are voltmeters of resistance R, 1.5 Rand 3R respectively as shown in the figure. Whensome potential difference is applied between X andY, the voltmeter readings are VA, VB and VCrespectivel...

A conducting square frame of side ′a′ and a long straight wire carrying current I are located in the same plane as shown in the figure. The frame moves to the right with a constant velocit...

The resistance of a wire is 'R' ohm. If it is melted and stretched to 'n' times its original length, its new resistance will be :-

A potentiometer is an accurate and versatile device to make electrical measurements of E.M.F. because the method involves :-

Figure shows a circuit that contains three identical resistors with resistance R = 9.0 Ω each, two identical inductors with inductance ε = 2.0 mH each, and an ideal battery with emf e = 18 V...

A square loop ABCD carrying a current i, is placed near and coplanar with a long straight conductor XYcarrying a current I, the net force on the loop will be:...

Consider the junction diode as ideal. The value of current flowing through AB is:...

The charge flowing through a resistance R varies with time t as Q=at - bt2 where a and b are positiveconstants. The total heat produced in R is :

A potentiometer wire is 100 cm long and a constant potential difference is maintained across it. Two cellsare connected in series first to support one another and then in opposite direction. The balan...

The reading of the ammeter for a silicon diode in the given circuit is :-...

In a potentiometer experiment, it is found that no current passes through the galvanometer when the terminals of the cell are connected across 52 cm of the potentiometer wire. If the cell is shunte...

On interchanging the resistances, the balance point of a meter bridge shifts to the left by 10 cm. The resistance of their series combination is 1 kΩ. How much was the resistance on the left slot ...

Two batteries with e.m.f 12 V and 13 V are connected in parallel across a load resistor of 10Ω. The internal resistances of the two batteries are 1Ω and 2Ω respectively. The voltage across the lo...

A set of 'n' equal resistors, of value 'R' each, are connected in series to a battery of emf 'E' and internal resistance 'R'. The current drawn is I. Now, the 'n&#3...

A battery consists of a variable number 'n' of identical cells (having internal resistance 'r' each) which are connected in series. The terminals of the battery are short-circuited and...