Objective Questions on Measuring Instruments for Electrician Trade
| Sr. No. | Questions with options |
| 1 | Which force is required to move the pointer from zero position in an indicating instrument?
(a) Controlling force (b) Deflecting force (c) Air friction damping (d) Eddy current damping Ans- (b) |
| 2 | Which is the position to use the instrument provided with gravity control?
(a) Any position (b) Vertical position (c) Inclined position (d) Horizontal position Ans –(b) |
| 3 | Which error is caused by the incorrect position of instrument reading?
(a) Device error (b) Human error (c) Influence error (d) Switching error Ans – (a) |
| 4 | Which instrument is used to measure one ohm and below one ohm resistance value accurately?
(a) Megohm meter (b) Multimeter (analog0 (c) Shunt type ohm meter (d) Series type ohm meter Ans-(c) |
| 5 | What is the purpose of the 3rd terminal provided in a advanced megohm meter?
(a) Get higher ohmic values (b) Pass the excess voltage to ground (c) Pass the excess current to ground (d) Get accurate readings without oscillation Ans – (d) |
| 6 | What is the reason for the moving coil meter having uniform scale?
(a) Deflecting torque is directly proportional to the current (b) Deflecting torque is inversely proportional to the current (c) Deflecting torque is inversely proportional to the square of the current (d) Deflecting torque is directly proportional to the square of the current Ans – (a) |
| 7 | Which error if the energy meter disc rotating continuously on no load?
(a) Speed error (b) Phase error (c) Friction error (d) Creeping error Ans – (d) |
| 8 | What is the effect on CT if its secondary is kept open?
(a) CT primary burns out (b) Volt ampere capacity reduces (c) Volt ampere capacity increases (d) CT secondary winding burns out Ans – (d) |
| 9 | What is the purpose of variable resistor connected across shunt type ohm meter?
(a) Avoid draining of battery (b) Minimize the error in reading (c) Adjust the current to safe value (d) Adjust the pointer to zero adjustment Ans – (d) |
| 10 | Which material is used to make control spring in measuring instruments?
(a) Steel (b) Silver (c) Tinned copper (d) Phosphor bronze Ans – (d) |
| 11 | Which electrical effect that the single phase energy meter works?
(a) Heating effect (b) Induction effect (c) Chemical effect (d) Electrostatic effect Ans – (b) |
| 12 | Which position an instrument using fluid friction damping reads accurately?
(a) Any position (b) Vertical position only (c) Inclined position only (d) Horizontal position only Ans – (a) |
| 13 | Which instrument is an example of an integrating instrument?
(a) AC voltmeter (b) DC voltmeter (c) Energy meter (d) Tangent galvanometer Ans – (d) |
| 14 | How the creeping error is controlled in energy meter?
(a) By reducing rated voltage (b) By increasing the inductive load (c) By adjusting the brake magnet position (d) By drilling two holes diametrically opposite on disc Ans – (d) |
| 15 | Why the scale of the moving iron instrument is having un-uniform scale?
(a) Deflecting force is directly proportional to the current (b) Deflecting force is inversely proportional to the current (c) Deflection of force is directly proportional to the square of the current (d) Deflection force is inversely proportional to the square of the current Ans –(c) |
| 16 | Which source of measuring error is caused by the effect of magnetic fields?
(a) Device error (b) Human error (c) Influence error (d) Switching error Ans – (c) |
| 17 | Which type of instrument is used with air friction damping?
(a) Moving coil instrument (b) Moving iron instrument (c) Induction type instrument (d) Dynamo meter type instrument Ans – (b) |
| 18 | Which type of energy meter works with netural connection?
(a) Three phase two element (b) Three phase three element (c) Single phase single element (d) Three phase two element with CT & PT Ans – (c) |
| 19 | What is the unit of sensitivity in instrument?
(a) Volt/ ohm (b) Ohm/volt (c) Ohm meter (d) Ohm/meter Ans – (b) |
| 20 | Why two straight holes are provided in the aluminium disc in energy meter?
(a) To reduce the disc weight (b) For power factor correction (c) To prevent the flux leakage (d) To arrest the creeping error Ans – (d) |
| Published On – 3rd June 2022 | |
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