Measuring Instruments MCQ

31. A null type of instrument as compared to a deflection type instrument has

1. A faster response
2. A lower sensitivity
3. A higher accuracy
4. All of these

32. In __________ instruments the deflecting torque depends on the frequency

1. Induction type instruments
2. Hot wire instruments
3. Moving iron instruments
4. Moving coil instruments

33. In force-voltage, the spring constant is analogous to ________ in an electrical system.

1. Reciprocal of inductance
2. Reciprocal of resistance
3. Ratio of inductance and resistance
4. Reciprocal of capacitance

34. Which meter has the highest accuracy in the prescribed limit of the frequency range

1. Rectifier
2. Electrodynamic meter
3. PMMC
4. Moving iron

35. The most efficient form of damping employed in electrical instruments is

1. Air friction
2. Fluid friction
3. Eddy currents
4. None of these

36. In a critically damped system, the damping factor of the system is

1. Zero
2. Less than unity
3. Unity
4. Greater than unity

37. A linear scale used in

1. Thermocouple meters
2. Moving iron meters
3. Hotwire meters
4. None of these

38. In a gravity controlled instrument, the deflection angle is proportional to

1. Measured value
2. Square of measured value
3. Sine inverse of measured value
4. Sine of measured value

39. In the below given deflecting torque equation “B” indicates

Equation: Deflecting torque=N.B.A.I

1. Constant
2. Flux density
3. Current flowing throughout the meter
4. Number of turns in the coil

40. Which of the following describes the linearity of an instrument?

1. Largest change in measured variable which produces no instrument response
2. Closeness of the calibration curve to a specified straight line
3. Closeness of the indicated value to the measured
4. Range of an inaccuracy which can be tolerated