Swithcgear and Protection MCQ Questions Part 2
Contents
- 1 The fuse element is usually made of
- 2 Most of relays in Electrical Power Systems are
- 3 A circuit breaker on its own performs the function of
- 4 A circuit breaker is able to open under
- 5 As compared to circuit breaker the fuse is
- 6 Current chopping mainly occurs in
- 7 Two fuse having wires of same material have fusing currents of 10 A and 15 A. The 10 A fuse has
- 8 Which of following is an advantage of a low oil circuit breaker over the bulk oil circuit breaker
- 9 Rate of rise of restriking voltage depends on
- 10 The making capacity of a circuit breaker is expressed mathematically as
The fuse element is usually made of
The fuse element is usually made of:
- Silver
- Steel
- Brass
- Iron
Correct answer: 1. Silver
Most of relays in Electrical Power Systems are
Most of relays in Electrical Power Systems are:
- Thermal relays
- Electronic relays
- Electromechanical relays
- Microprocessor relays
Correct answer: 3. Electromechanical relays
A circuit breaker on its own performs the function of
A circuit breaker on its own performs the function of:
- Circuit interruption only
- Detection only
- Both detection and circuit interruption
- None or above
Correct answer: 1. Circuit interruption only
A circuit breaker is able to open under
A circuit breaker is able to open under:
- No-load conditions
- Loaded conditions
- Fault conditions
- All of these
Correct answer: 4. All of these
As compared to circuit breaker the fuse is
As compared to circuit breaker the fuse is
- Is costlier
- Of same cost
- Is cheaper
- None of these
Correct answer: 3. Is cheaper
Current chopping mainly occurs in
Current chopping mainly occurs in:
- Vacuum circuit breaker
- Oil circuit breaker
- Sf6 circuit breaker
- Air-blast circuit breaker
Correct answer: 4. Air-blast circuit breaker
Two fuse having wires of same material have fusing currents of 10 A and 15 A. The 10 A fuse has
Two fuse having wires of same material have fusing currents of 10 A and 15 A. The 10 A fuse has:
- Smaller diameter
- Larger diameter
- Both will have same
- None of these
Correct answer: 1. Smaller diameter
Explanation: Fusing current is directly proportional to current by formula:
I ∝ d^3/2
Which of following is an advantage of a low oil circuit breaker over the bulk oil circuit breaker
Which of following is an advantage of a low oil circuit breaker over the bulk oil circuit breaker:
- It requires less space
- It reduces risk of fire
- It requires comparatively less oil
- All of these
Correct answer: 4. All of these
Rate of rise of restriking voltage depends on
Rate of rise of restriking voltage depends on:
- Capacitance of system
- Inductance of system
- Type of circuit breaker
- Inductance and Capacitance of system
Correct answer: 4. Inductance and Capacitance of system
The making capacity of a circuit breaker is expressed mathematically as
The making capacity of a circuit breaker is expressed mathematically as:
- 2.55 x Symmetrical breaking capacity
- √2 x Symmetrical breaking capacity
- √3 x Symmetrical breaking capacity
- √4 x Symmetrical breaking capacity
Correct answer: 1. 2.55 x symmetrical breaking capacity