Exercise: Measurements And Instrumentation

Questions for: Measurements And Instrumentation

Assertion (A): If the resistance of shunt of an ammeter is increased, the range of ammeter is reduced.

Reason (R): If the series resistance of a voltmeter is increased, the range of voltmeter is increased.

A:
Both A and R are true and R is correct explanation of A
B:
Both A and R are true but R is not correct explanation of A
C:
A is true R is false
D:
A is false R is true
Answer: B
No answer description is available. Let's discuss.
📖
📝
💬
👁️
The ac bridge in figure is balanced. Z1 = 100∠30°, Z2 = 150∠0°, Z3 = 250∠ - 40° Then Z4 =
A:
375∠70° Ω
B:
375∠ - 70° Ω
C:
150∠0° Ω
D:
150∠20° Ω
Answer: B

.

📖
📝
💬
👁️
An ammeter has a resistance of 50 ohms and a shunt of 0.01 Ω. The deflection is θ. If the shunt resistance is increased to 0.02 Ω, the deflection will be.
A:
θ
B:
2θ
C:
0.5θ
D:
0.25θ
Answer: B

Since shunt resistance is doubled, current through ammeter is doubled (current division for resistances in parallel). Therefore reading is 2 θ.

📖
📝
💬
👁️
In electronic voltmeters the measuring device is a
A:
moving coil instrument
B:
moving iron instrument
C:
dynamometer instrument
D:
none of the above
Answer: A

The a.c. voltage is rectified and measured by PMMC instrument.

📖
📝
💬
👁️
Moving iron instrument can be used for ac only.
A:
True
B:
False
C:
D:
Answer: B

Moving iron instruments can be used for both dc and ac.

📖
📝
💬
👁️
Ad Slot (Above Pagination)
Quiz