InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
The Lissajous pattern observed on screen of CRO is a straight line inclined at 45° to x axis. If -plate input is 2 sin ω, the -plate input is |
| Answer» When signals to X and Y plates are in phase, the display is a straight line inclined at 45°. | |
| 152. |
The angle δ for a mica capacitor is about |
| Answer» Mica capacitor has very low loss and loss angle δ is very very small. | |
| 153. |
A digital voltmeter has a read out range from 0 to 999 counts. If the full scale reading is 9.999 V, the resolution is |
| Answer» Resolution is the smallest change in the quantity being measured which will cause an observable change in output. In this case it is 1 mV. | |
| 154. |
The coil of a moving coil meter has 100 turns, is 40 mm long and 30 mm wide. The control torque is 240 x 10 N-m on full scale. If = 1 Wb/m, range of meter is |
| Answer» NBAI = Controlling torque or = 240 x 10-6 or I = 2 mA. | |
| 155. |
A meter with a resistance of 100 Ω and a full scale deflection of current of 1 mA is to be converted into voltmeter of 0 - 5 V range. The multiplier resistance should be |
| Answer» . | |
| 156. |
In a resistance strain gauge, G = 2, stress = 1050 kg/cm, R = 1000 Ω. The value of ΔR will be |
| Answer» . | |
| 157. |
The household energy meter is |
| Answer» It integrates energy over a period of time. | |
| 158. |
A standard cell of 1.0185 V is used with a slide wire potentiometer. The balance was obtained at 60 cm. When an unknown emf was connected, the balance was obtained at 82 cm. The magnitude of unknown emf is |
| Answer» . | |
| 159. |
Potentiometer method of dc voltage measurement is more accurate than direct measurement using a voltmeter because |
| Answer» Since the circuit is not loaded, the accurate value of dc voltage is measured. | |
| 160. |
A full wave rectifier type meter is used to measure the wave shape shown in figure. The voltmeter is calibrated to read rms value of sine wave. The reading of voltmeter will be |
| Answer» Peak value of sine wave = 100 x 1.11 = 111 V. | |
| 161. |
A moving coil instrument has a resistance of 0.5 Ω and a full scale deflection of 0.1 A. To convert it into an ammeter of 0-10 A the shunt resistance should be |
| Answer» . | |
| 162. |
A digital frequency counter can be converted to DVM by addition of a suitable |
| Answer» D/A converter changes digital output to analog output. | |
| 163. |
A dynamometer wattmeter is connected in ac circuit. The reading will be |
| Answer» Wattmeter measures average power over a cycle. | |
| 164. |
The speed transducer using a drag cup rotor has the main advantage of |
| Answer» A drag cup rotor has low inertia. Therefore it requires little amount of energy. | |
| 165. |
A voltmeter using thermocouples measures |
| Answer» Since the thermocouple is based on heating effect, rms value is measured. | |
| 166. |
In a thermocouple temperature transducer, the output voltage is usually measured by |
| Answer» The output voltage is very small. So we need a milli voltmeter. | |
| 167. |
A moving iron instrument gives correct reading when used at |
| Answer» If frequency changes reactance of coil changes and reading is affected. | |
| 168. |
Induction wattmeter can be used in |
| Answer» Induction effect occurs with ac only. | |
| 169. |
It is required to measure angular position. Out of the transducers The proper devices are |
| Answer» LVDT and E pickup are suitable for linear displacement. | |
| 170. |
In figure the bridge is balanced when Z is |
| Answer» . | |
| 171. |
In which of the transformer is the secondary nearly short circuited under normal operating conditions? |
| Answer» CT is operated with secondary short-circuited otherwise a high emf would be induced across secondary. | |