In a transformer, zero voltage regulation at full load is:
Not possible
Possible at unity power factor load
Possible at leading power factor load
Possible at lagging power factor load
Answer: Option C.
The zero voltage regulation at full load is possible at leading power factor load.
The DC motor, which can provide zero speed regulation at full load without any controller is :
Series
Shunt
Cumulative compound
Differential compound
Answer: Option B.
The speed and armature current characteristics of DC motor show that the speed of shunt motor is almost constant load. Therefore, shunt motor can provide zero speed regulation
The concept of an electrically short, medium , and long line is primarily based on the
Nominal voltage of the line
Physical length of the line
Wavelength of the line
Power transmitted over the line
Answer: Option B.
The concept of electrically short, medium and long line is primarily based on the physical length of the line.
Keeping in view the cost and overall effectiveness, which of the following circuit breakers is best suited for capacitor bank switching?
Vacuum
Air blast
SF6
Oil
Answer: Option A.
Because of short gal and excellent recovery characteristics of vacuum breakers they can be used where the switching frequency is high and required to be reliable and maintenance required is also least. Hence, suitable for capacitor bank switching.
Feedback control systems are
Insensitive to both forward and feedback path parameter changes
Less sensitive to feedback path parameter changes than to forward path parameter changes
Less sensitive to forward path parameter changes than to feedback path parameter changes
Equally sensitive to forward and feedback path parameter changes.
The effect of stray magnetic fields on the actuating torque of a potable instrument is maximum when the operating field of the instrument and the stray fields are
Perpendicular
Parallel
Inclined at 600
Inclined at 300
Answer: Option B.
Actuating torque is directly proportional to cos (angle between operating field and magnetic field) For maximum actuating torque both are parallel.
