A potentiometer is used to compare two emf sources. If the first source gives a
Practice Questions
Q1
A potentiometer is used to compare two emf sources. If the first source gives a balance length of 60cm and the second gives 90cm, what is the ratio of their emfs?
2:3
3:2
1:1
4:5
Questions & Step-by-Step Solutions
A potentiometer is used to compare two emf sources. If the first source gives a balance length of 60cm and the second gives 90cm, what is the ratio of their emfs?
Step 1: Understand that a potentiometer is used to measure the electromotive force (emf) of two different sources.
Step 2: Note the balance lengths given for each emf source. The first source has a balance length of 60 cm, and the second source has a balance length of 90 cm.
Step 3: Recognize that the ratio of the emfs is the same as the ratio of the balance lengths.
Step 4: Write the ratio of the balance lengths: 60 cm for the first source and 90 cm for the second source.
Step 5: Simplify the ratio 60 cm:90 cm by dividing both numbers by their greatest common divisor, which is 30.
Step 6: After simplification, the ratio becomes 2:3.
Potentiometer Principle – A potentiometer measures the electromotive force (emf) of a source by balancing it against a known reference, where the balance length is directly proportional to the emf.
Ratio Comparison – The ratio of the emfs of two sources can be determined by comparing the lengths at which they balance on the potentiometer.
