Potentiometer Principle
Potentiometer measures EMF accurately because it draws:
Select the correct option:
🔒 Solution Hidden from View
Submit your answer to unlock the detailed step-by-step solution.
More current electricity Practice Questions
A potentiometer is often preferred over a voltmeter for measuring the emf of a cell accurately, so w...
A potentiometer is often preferred over a voltmeter for measuring the emf of a cell accurately, so w...
Three identical cells, each with internal resistance 0.6 ohm, are connected in parallel to reduce th...
Three identical cells, each with internal resistance 0.6 ohm, are connected in parallel to reduce th...
A battery of emf 12 volts and internal resistance 3 ohm drives a variable load resistor, so for what...
A battery of emf 12 volts and internal resistance 3 ohm drives a variable load resistor, so for what...
Engineers relate the current density inside a conductor to the local electric field through the mate...
Engineers relate the current density inside a conductor to the local electric field through the mate...
An electric heater rated to carry 5 amperes operates across a 220 volt mains supply in a kitchen, so...
An electric heater rated to carry 5 amperes operates across a 220 volt mains supply in a kitchen, so...
Current passes through a 20 ohm resistor at 2 amperes for 5 minutes in a demonstration, so how much ...
Current passes through a 20 ohm resistor at 2 amperes for 5 minutes in a demonstration, so how much ...
Four identical cells, each of emf 1.5 volts and internal resistance 0.2 ohm, are connected in series...
Four identical cells, each of emf 1.5 volts and internal resistance 0.2 ohm, are connected in series...
Two resistors of 6 ohm and 3 ohm are wired side by side between the same two nodes of a circuit, so ...
Two resistors of 6 ohm and 3 ohm are wired side by side between the same two nodes of a circuit, so ...
A cell of emf 6 volts and internal resistance 0.5 ohm is connected to an external resistor of 2.5 oh...
A cell of emf 6 volts and internal resistance 0.5 ohm is connected to an external resistor of 2.5 oh...
While measuring a battery on a test bench, its terminal voltage drops from 12 volts on open circuit ...
While measuring a battery on a test bench, its terminal voltage drops from 12 volts on open circuit ...
At a junction in a network, currents of 5 A and 3 A enter while currents of 4 A and I leave through ...
At a junction in a network, currents of 5 A and 3 A enter while currents of 4 A and I leave through ...
Applying the loop rule around any closed mesh of a resistive network sets the algebraic sum of certa...
Applying the loop rule around any closed mesh of a resistive network sets the algebraic sum of certa...
About This Question
- Subject
- physics
- Chapter
- current electricity
- Topic
- potentiometer principle
- Difficulty
- Medium
- Year
- 2025
Solution
Correct Answer:
Zero current from source
A potentiometer uses the Null Point method.
- At the balancing point, the potential from the secondary circuit exactly matches that from the potentiometer wire segment.
- Consequently, no current flows from the test cell (I=0).
- Since V=E−Ir and I=0, the potentiometer measures the actual EMF (E) rather than the terminal voltage (V). This makes it a primary measurement tool unlike a voltmeter which always draws some current.
This medium difficulty physics question is from the chapter current electricity, covering the topic of potentiometer principle. It appeared in the 2025 exam.
Looking for more practice? Explore all physics questions or browse current electricity questions on RankGuru.