A cell of e.m.f. 4 V and of negligible internal resistance is connected in series with a potentiometer wire of length 400 cm. The e.m.f. of a Leelanche cell is found to be balacned at 150 cm from the positive end of the potentiometer wire. What is the e.m.f. of the Leclanche cell ?

A cell of e.m.f. 2 V and negligible internal resistance is connected to a potentiometer wire of resistance 10 Omega and length 4 m. The potential difference per unit length (potential gradient ) of the wire is

n cells of e.m.f E and internal resistance r are connected in series with an external resistance R . the current will increase n times that of a single cell, if

The e.m.f of the following galvanic cell:

If the e.m.f of a galvanic cell is neagative, it implies that:

Why is a potentiometer preferred over a voltmeter for determining the e.m.f. of a cell?

A potentiometer wire of length 100 cm has a resistance of 10Omega. It is connected in series with a resistance and an accumulator of emf 2V and negligible internal resistance. A source of emf 10 mV is balanced against a length of 40 cm of the potentiometer wire. what is the value of the external resistance?

Ten identical cells each of e.m.f. E and internal resistance r are connected in series to form a closed circuit. An ideal voltmeter connected across three cells, will read