Electronics and Communication Engineering - Measurements and Instrumentation

6.
The loss of charge method can be used to measure
resistance of shunt
insulation resistance of cable
resistance of shunt winding
both (b) and (c)
Answer: Option
Explanation:

It is used for measuring very high resistance.


7.

Assertion (A): Maxwell bridge is for measuring inductance of medium magnitude.

Reason (R): In Maxwell's bridge the unknown inductance is measured by comparing it with a capacitance.

Both A and R are true and R is correct explanation of A
Both A and R are true but R is not correct explanation of A
A is true R is false
A is false R is true
Answer: Option
Explanation:

Maxwell bridge does not use a capacitor.


8.

Assertion (A): A semiconductor strain gauge is more accurate than a resistance strain gauge.

Reason (R): The gauge factor of a semiconductor strain gauge is about 100 where as the gauge factor of a resistance strain gauge is only about 2.

Both A and R are true and R is correct explanation of A
Both A and R are true but R is not correct explanation of A
A is true R is false
A is false R is true
Answer: Option
Explanation:

Higher gauge factor results in better accuracy.


9.
Current density has the dimensions
IL
IL-2
IL-3
I2L-2
Answer: Option
Explanation:

Current density = current/area = IL-2.


10.
The resistance of a dc galvanometer is 20 Ω. A current of 10 mA causes full scale deflection. To convert it into 0-300 V voltmeter, we have to use a series resistance of
30000 Ω
29980 Ω
6000 Ω
15 Ω
Answer: Option
Explanation:

.