Essentials of indicating instrument - Electrical Engineering (MCQ) questions and answers

1)   The spring which is used for producing controlling torque in indicating instruments are made up of materials which is / are

a. Non - magnetic
b. Not subjected to much fatigue
c. Low specific resistance and low temperature resistance coefficient
d. All of these
Answer  Explanation 

ANSWER: All of these

Explanation:
No explanation is available for this question!


2)   The scales of gravity controlled instruments are

a. Uniform
b. Non - uniform and cramped or crowded at the middle
c. Non - uniform and cramped or crowded at their lower ends
d. Non - uniform and cramped or crowded in the first half
Answer  Explanation 

ANSWER: Non - uniform and cramped or crowded at their lower ends

Explanation:
No explanation is available for this question!


3)   Due to overdamping, the instrument will become

a. Slow
b. Lethargic
c. Fast
d. Both (a) and (b)
Answer  Explanation 

ANSWER: Both (a) and (b)

Explanation:
No explanation is available for this question!


4)   If the degree of damping of an instrument should be adjusted to a value which is sufficient to enable the pointer to rise quickly to its deflected position without overshooting is called as

a. Overdamped
b. Dead beat
c. Underdamped
d. None of these
Answer  Explanation 

ANSWER: Dead beat

Explanation:
No explanation is available for this question!


5)   Damping torque is the torque which acts on

a. Stationary system of the instrument
b. Moving system of the instrument only when it is stationary
c. Moving system of the instrument only when it is moving
d. Stationary system of the instrument only when the moving system is moving
Answer  Explanation 

ANSWER: Moving system of the instrument only when it is moving

Explanation:
No explanation is available for this question!


6)   A deflection of 90 degree is produced when a current of 10 A flows through the circuit and the torque of the ammeter vary as the square of the current through it. If a current of 8 A flows through it, then the deflection obtained when the instrument is spring controlled and when the instrument is gravity controlled are

a. 39.79 degree, 57.6 degree
b. 47.55 degree, 35.67 degree
c. 57.6 degree, 39.79 degree
d. 35.67 degree, 47.55 degree
Answer  Explanation 

ANSWER: 57.6 degree, 39.79 degree

Explanation:
No explanation is available for this question!


7)   The gravity controlled instruments has to be kept

a. Vertical
b. Horizontal
c. Inclined at 45 degree
d. Inclined at 75 degree
Answer  Explanation 

ANSWER: Vertical

Explanation:
No explanation is available for this question!


8)   In a gravity controlled type indicating instrument, the current flowing through the circuit is

a. Directly proportional to the cosine of angle of deflection
b. Directly proportional to the sine of angle of deflection
c. Directly proportional to the tan of the angle of deflection
d. Directly proportional to the angle of deflection
Answer  Explanation 

ANSWER: Directly proportional to the sine of angle of deflection

Explanation:
No explanation is available for this question!


9)   In measuring instruments, spiral springs are provided to

a. Lead current
b. Produce controlling torque
c. Produce damping torque
d. Lead current and produce controlling torque
Answer  Explanation 

ANSWER: Lead current and produce controlling torque

Explanation:
No explanation is available for this question!


10)   In a spring controlled type indicating instruments, if the controlling torque is equal to the deflecting torque then

a. Angle of deflection will be maximum
b. Current flowing through it will be maximum
c. Angle of deflection will be zero
d. Angle of deflection will be directly proportional to the current flowing through it
Answer  Explanation 

ANSWER: Angle of deflection will be directly proportional to the current flowing through it

Explanation:
No explanation is available for this question!


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