Potentiometer

The video tutorial explains the use of a potentiometer, a device similar to a meter bridge but with a longer resistance wire for greater accuracy. It describes how a standard cell maintains a constant current, allowing the potentiometer to compare the EMF of two cells using a two-way key and Kirchoff's loop rule. The tutorial also covers measuring the internal resistance of a cell by connecting it across a resistance box. The potentiometer's advantage is that it draws no current from the voltage source, making it unaffected by the source's internal resistance.

What is the primary advantage of using a potentiometer over a meter bridge?

• It requires less maintenance.

• It is cheaper to manufacture.

• It allows for greater accuracy due to a longer resistance wire.

• It can measure temperature changes.

In the potentiometer setup, what role does the standard cell of EMF e1 play?

• It acts as a backup power source.

• It measures the potential difference.

• It maintains a constant current throughout the wire.

• It provides a variable current.

How does the potentiometer compare the EMF of two cells?

• By measuring the temperature difference.

• By using a two-way key and balancing the EMFs.

• By calculating the resistance difference.

• By using a digital display.

What is the purpose of the resistance box in measuring internal resistance with a potentiometer?

• To act as a safety device.

• To help determine the internal resistance of the cell.

• To adjust the current flow.

• To provide a constant voltage.

Why is the potentiometer unaffected by the internal resistance of the source?

• Because it is made of a special material.

• Because it has a built-in compensator.

• Because it draws no current from the voltage source being measured.

• Because it uses a digital meter.