(a) high voltage and high current.
(b) low voltage and high current.
(c) low voltage and low current.
(d) high voltage and low current.
Answer: (b) low voltage and high current.
Explanation:
CONCEPT: Homopolar Generator
A homopolar generator (also called a Faraday disc generator) produces direct current (DC).
It operates on the principle of motional EMF, where a conducting disc rotates in a magnetic field.
Unlike conventional generators, it does not produce alternating EMF internally.
Output Characteristics
Low Voltage
The generated EMF in a homopolar generator is:
Relatively small
Typically a few volts in small and medium-sized machines
The voltage is low because:
The effective length of the conductor cutting the magnetic field is small
EMF is generated across the radius of the disc
High Current
Homopolar generators have:
Very low internal resistance
Due to this:
They can supply extremely large currents
Large experimental machines can deliver hundreds of kiloamperes to millions of amperes
This makes them suitable for applications such as:
Welding
Railguns
Pulse power systems
EXPLANATION
Since:
Output voltage is low
Internal resistance is extremely small
The generator delivers very high current at low voltage.
Why Other Options Are Incorrect
(a) High voltage and high current ❌
Homopolar generators cannot generate high voltage due to design limitations.
(c) Low voltage and low current ❌
Although voltage is low, current capability is very high.
(d) High voltage and low current ❌
This behavior is typical of some electrostatic machines, not homopolar generators.
FINAL ANSWER
✅ Correct option: (b)
Low voltage and high current
✔️ Key One-Line Exam Statement
A homopolar generator produces low voltage but extremely high current due to its very low internal resistance.