 # Electrical Measurements

1. Which of the following are the more accurate instrument?
a. Tangent galvanometer
b. Potentiometer
c. Both a & b
d. Hot wire meter
2. Which of the following is absolute instrument?
a. Rayleigh current meter
b. Pointing meter
c. Both a & b
d. Thermo coupled meter
3. 115ohm is measured in the following 3 ways
which of the following is true?
1. 115ohm 2. 115.0ohm 3. 0.115*10^3
a. 1&3 is same precision , 2 high precision
b. 1&2 is same precision, 3 high precision
c. 1,2&3 is same precision
d. insufficient data
4. For a (0-30)A ammeter, the input and output readings are shown in below figure. Calculate
output non-linearity and input linearity in instrument.
input(amp) 0 5 10 15 20 25 30
output(amp) 0 6 12 18 21 26 29
5. a. What is the range and span of the 9(0-300)v voltmeter?
b. A thermistor measures a temperature of -15degree c and 45 degree c
6. A (0-200)v voltmeter having 100 division and (1/10) of each division can be estimated the resolution of the voltmeter is?
7. A pyrometer dead zone is 10% of span of instrument. If the scale of the pyrometer is calibrated as (10deg.c -20deg.c). Calculate the change in input before output is calculated?
8. In a wheat stone bridge, change of 10ohm in arm resistance causes 2mm deflection in galvanometer, calculate
1. Sensitivity
2. Deflection factor
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