Electronics and Communication Engineering - Networks Analysis and Synthesis

31.
Energy = voltage x charge.
True
False
Answer: Option
Explanation:

Energy = voltage x current x time = voltage x charge.


32.
A coil is wound having a diameter d. Its inductance is 10 mH. If it is rewound on the same core with a wire having diameter 0.5 d and total weight of the wire is the same as before, the inductance will be
5 mH
10 mH
160 mH
40 mH
Answer: Option
Explanation:

Since diameter is halved, area of cross-section is one-fourth. The number of turns becomes four times. Inductance = μ N2.


33.
Permeability is analogous to
conductivity
resistivity
retentivity
coercivity
Answer: Option
Explanation:


34.
A resistance and an inductance are connected in parallel and fed from 50 Hz ac mains. Each branch takes a current of 5 A. The current supplied by source is
10 A
7.07 A
5 A
zero
Answer: Option
Explanation:

The current is 5 - j5 = 52 + 52 = 7.07 A.


35.

Assertion (A): The inductance of an iron cored solenoid is not constant.

Reason (R): BH curve of an iron specimen is non-linear.

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

Since B-H curve is non-linear, the inductance of iron cored solenoid is not constant.