1. If reference sound pressure P0 is 2 x 10-5 N/m2, a sound pressure of 90 dB is equal to
2. Which of the following voltmeters would you use for measuring voltage across 20 kΩ resistance?
3. A single phase energy meter has the rating 1200 resolutions/ kWh. If a 500 W electric gadget is used for 4 hours, the energy meter will make
4. Assertion (A): De sauty's bridge is suitable only for pure capacitor.Reason (R): Capacitors are mostly perfect.
5. In which of the transformer is the secondary nearly short circuited under normal operating conditions?
6. A moving coil instrument has a resistance of 0.6 Ω and full scale deflection at 0.1 A. To convert it into an ammeter of 0-15 A range, the resistance of shunt should be
7. A piezoelectric force transducer has a charge sensitivity of 20 pC/N. It is connected to a charge amplifier and overall gain of transducer and amplifier is 50 mV/N. The gain of amplifier is
8. An LVDT is used to measure displacement. The LVDT feeds a Voltmeter of 0-5 V range through a 250 gain amplifier. For a displacement 0.5 mm the output of LVDT is 2 mV. The sensitivity of instrument is
9. Assertion (A): When a wattmeter is used for low impedance loads, the pressure coil is connected across the load.Reason (R): A wattmeter measures apparent power.
10. As per BIS there are 6 accuracy classes of instruments.
11. In figure, Z1 = 200∠60° Ω, Z2 = 400∠ - 90° Ω, Z3 = 300∠0°. Then Z4 for bridge to be balanced is
12. In a ballistic galvanometer, a charge of 100 μC gives a first swing of 25°. The charge required to cause first swing of 50° is
13. Two resistors R1 = 36 Ω ± 5% and R2 = 75 Ω ± 5% are connected in series. The total resistance is
14. Figure shows an RC potentiometer to measure ac voltage. It is desired that V0/Vi should be independent of frequency. The value of C should be
15. In a strain measuring device using a strain gauge, the output quantity is
16. The Lissajous pattern observed on screen of CRO is a straight line inclined at 45° to x axis. If X-plate input is 2 sin ωt, the Y-plate input is
17. The angle δ for a mica capacitor is about
18. 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
19. The coil of a moving coil meter has 100 turns, is 40 mm long and 30 mm wide. The control torque is 240 x 10-6 N-m on full scale. If B = 1 Wb/m2, range of meter is
20. Consider the following statements: In a differential amplifier using JFET, the differential output offset is due to mismatch between FET parametersdifference in values of resistances used in circuitvariation in supply voltage. Of the statements, the correct statements are
21. Magnetic flux density has the dimensions
22. 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
23. In a resistance strain gauge, G = 2, stress = 1050 kg/cm2, R = 1000 Ω. The value of ΔR will be
24. The household energy meter is
25. 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