In a tungsten filament lamp - Networks Analysis and Synthesis

Electronics and Communication Engineering (ECE) : Networks Analysis and Synthesis - Quiz(MCQ)

In a tungsten filament lamp

the current at the instant of switching is equal to operating current

the current at the instant of switching is less than operating current

the current at the instant of switching is more than operating current

the current at the instant of switching may be less than or equal to operating current

Correct Answer : Option (D) : the current at the instant of switching may be less than or equal to operating current

Explanation : Resistance at the time of switching on is minimum and increases due to increase of temperature.

Recently Updated in Networks Analysis and Synthesis Questions

Ohm's law is valid for

dc voltage and current

ac voltage and current

dc and ac voltages and currents

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

11 Ω

16 Ω

22 Ω

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

90°

180°

270°

360°

Correct Answer :

360°

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