Would you prefer a vlotmeter over a potentiomer to measure the emf of a battery?

Why do we prefer a potentiometer to measure emf of a cell rather than a voltmeter ?

Describe in steps, how would you use a vernier callipers to measure the length of a small rod ?

Assertion A potentiometer is preferred over that of a voltmeter for measurement of emf of a cell Reason potentiometer does not draw any current from the cell.

The length of a wire of a potentiometer is 100 cm, and the e.m.f. of its standard cell is E volt. It is employed to measure the e.m.f. of a battery whose internal resistance is 0.5 Omega . If the balance point is obtained at I = 30 cm from the positive end, the e.m.f. of the battery is . where i is the current in the potentiometer wire.

Would you prefer to slide or roll a log of wood along the road? Why?

Would you prefer a material having a high melting point or a low melting point to be used as a cathode in a diode?

The emf of a battery A is balanced by a length of 80cm on a potentio meter wire. The emf of a standard cell 1v is balanced by 50cm. The emf of A is

In the simple L-R circuit, can the emf induced across the inductor ever be greater than the emf of the battery used to produce the current?

A : parctically a voltmeter will measure the voltage across the battery but not its EMF. R : EMF of a cell is measured with the help of a potentiometer .

A : The voltage across a battery may be less, equal or more than the emf of the battery. R : Voltage across a battery also depends on the magnitude and direction of current .