If the diameter of a wire is doubled, the current carrying capacity of the wire becomes

A)
half
B)
twice
C)
four times
D)
one-fourth

Correct Answer : Option (C) :   four times

Explanation : Since diameter is doubled, area of cross-section becomes four times. Current carrying capacity is proportional to area of cross-section.

Recently Updated in Networks Analysis and Synthesis Questions
Ohm's law is valid for
A)
dc voltage and current
B)
ac voltage and current
C)
dc and ac voltages and currents
D)
all voltages and current

Correct Answer :   all voltages and current

Explanation : KCL and KVL are valid for voltages and currents of all wave shapes during transient as well as steady state conductions.

If e = 110 sin (ωt + p/3) and i = 5 sin (ωt - p/3), the impedance of the circuit is
A)
 
11 Ω
B)
16 Ω
C)
22 Ω
D)
30.8 Ω

Correct Answer :   22 Ω

Explaination :

Two phasors having rms values V1 and V2 which are added to give a phasor having rms value V3. V3 is maximum if phase angle between V1 and V2 is
A)
 
90°
B)
 
180°
C)
 
270°
D)
 
360°

Correct Answer :  

 
360°

Explaination : Sum of phasors is maximum if they are in phase and 360° = 0.

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