Current Electricity Physics - Current Electricity

Define potential gradient of the potentiometer wire.

What is shunt?

What is the value of resistance for an ideal voltmeter?

The e.m.f. of a cell is balanced by a length of \(320 cm\) of the potentiometer wire. When a cell is shunted by a resistance of \(50 \Omega\) the balancing length is reduced by \(20 cm\). Find internal resistance of the cell.

State any 'two' possible sources of errors in meter-bridge experiment. How can they be minimised?

A potentiometer wire has resistance of per unit length of \(0.1 \Omega / m\). A cell of e.m.f. \(1.5 V\) balances against \(300 cm\) length of the wire. Find the current in the potentiometer wire.

Four resistances \(4 \Omega, 8 \Omega, X \Omega\) and \(6 \Omega\) are connected in a series so as to form Wheatstone's network. If the network is balanced, find the value of \(X\).

Distinguish between potentiometer and voltmeter.

A potentiometer wire has a length of \(4 m\) and a resistance of \(5 \Omega\). What resistance should be connected in series with a potentiometer wire and a cell of e.m.f. \(2 V\) having internal resistance \(1 \Omega\) to get a potential gradient of \(10^{-3} V / cm\) ?

Two cells of emf \(4 V\) and \(2 V\) having respective internal respective internal resistance of \(1 \Omega\) and \(2 \Omega\) are connected in parallel, in so to send current in the same direction through an external resistance of \(5 \Omega\). Find the current through the external resistance.

Two resistances \(X\) and \(Y\) in the two gaps of a meter-bridge gives a null point dividing the wire in the ratio \(2: 3\). If each resistance is increased by \(30 \Omega\), the null point divides the wire in the ratio \(5: 6\), calculate the value of \(X\) and \(Y\).

When a resistor of \(5 \Omega\) is connected across the cell, its terminal potential difference is balanced by \(150 cm\) of potentiometer wire and when a resistance of \(10 \Omega\) is connected across cell, the terminal potential difference is balanced by \(175 cm\) same potentiometer wire. Find the balancing length when the cell is in open circuit and the internal resistance of the cell.

A cell balances against a length of \(200 cm\) on a potentiometer wire, when it is shunted by a resistance of \(8 \Omega\). The balancing length reduces by \(40 cm\), when it is shunted by a resistance of \(4 \Omega\). Calculate the balancing length when the cell is in open circuit. Also calculate the internal resistance of the cell.

Explain the conversion of a Moving Coil Galvanometer (MCG) into an ammeter. Obtain necessary formula.