Concept of Bulb(Rating and Power Generation)||Potentiometer(EMF OF Unknown Cell)

How to measure an unknown voltage using potentiometer.

Assertion: The emf of the cell in secondary circuit must be less than emf of cell in primary circuit in potentiometer. Reason: Balancing length cannot be more than length of potentiometer wire.

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.

Potentiometer|Principle|Potential Gradient|Application|To Compare EMF Of Two Cell

In an experiment to find the internal resistance of a cell by a potentiometer, a balance was obtained for 50 cm length of the potentiometer wire, with a cell of e.m.f. 2V. When the cell was shunted by a resistance of 2 Omega , the balancing length of the potentiometer wire was 40 cm. What was the internal resistance of the cell ?

With a certain cell the balance point is obtained at 70 cm from the zero and of the potentiometer wire. With another cell whose emf differs from the 60 cm mark .Calculate the emf of the two cells

A cell of emf (E) and internal resistance (r) is balanced across (l) length of potentiometer wire. If another cell of emf 2E and internal resistance (2r) is connected in parallel to the first cell , then the balancing length will be