A. inversely proportional to the current
B. inversely proportional to the square of the current
C. proportional to the current
D. proportional to square of the current
Answer: Option B
This Question Belongs to Electrical Engineering >> Switchgear Protections
Magnetic circuit breaker has ______ trip action.
A. delayed
B. instantaneous
C. both of the above
D. none of the above
In a circuit breaker the basic problem is to
A. maintain the arc
B. extinguish the arc
C. transmit large power
D. emit the ionizing electrons
The arcing contacts in a circuit breaker are made of
A. copper tungsten alloy
B. porcelain
C. electrolytic copper
D. aluminium alloy
Air blast circuit breaker is used for
A. over currents
B. short duty
C. intermittant duty
D. repeated duty
ans is D
Option D is the correct ans, as Torque(T) is proportional to I^2*Sin(alpha). Where alpha is the angle between flux produced by shaded portion and unshaded portion.