21. The moving system of an indicating type of electrical instrument is subjected to
- A defecting torque
- A controlling torque
- A damping torque
- All of the above
22. Determine the absolute error of measurement if the measured value of resistance of 20.65 Ω and true value = 20.55 Ω
- 0.1 Ω
- 0.2 Ω
- 0.3 Ω
- 0.4 Ω
23. Energy savings potential of variable torque applications compared to constant torque application is-
- Higher
- Minor
- Equivalent
- None of the above
24. The controlling torque in the power factor meter is given by
- Spring control
- Sensor control
- Gravity control
- None of the above
25. The effect of stray magnetic fields on the actuating torque of a portable instrument is the maximum when the operating field of the instrument and the stray fields are
- Perpendicular
- Parallel
- Inclined at 60°
- Inclined at 30°
26. Indicating instruments should be
- Undamped
- Critically damped
- Over damped
- Under damped
27. What is a Weston frequency meter?
- Moving coil instrument
- Moving iron instrument
- Dynamometer type instrument
- Induction instrument
28. To maximize the driving torque in an induction type instrument, the flux produced by shunt coil and series coil should be
- In phase with each other
- In quadrature with each other
- Displaced by 45° with respect to each other
- Out of phase with respect to each other
29. In indicating instruments the springs are mainly used to
- Conduct the current to the coils
- Hold the pivot in position
- Control the pointer movement
- Reduce the vibration of the pointer
30. _________ instrument is free from hysteresis and eddy current errors.
- Electrostatics
- Moving iron
- Moving coil-permanent magnet type
- Moving coil dynamometer type