A device ‘X’ is connected to an ac source V = V₀ sin(ωt). The variation of voltage, current and power in one complete cycle is shown in the following figure.
(i) Which curve shows power consumption over a full cycle?
(ii) Identify the device ‘X’.
(i) Which curve shows power consumption over a full cycle?
(ii) Identify the device ‘X’.
(i) A
(ii) Capacitor
Detailed Answer :
(i) Power's frequency is double of current or voltage frequency.
(ii) From the graph, the phase difference between V and I is so device ‘X’ may be an inductor (L) or capacitor (C) but since current (graph C) leads the voltage (graph B), device is capacitor.
(ii) Capacitor
Detailed Answer :
(i) Power's frequency is double of current or voltage frequency.
(ii) From the graph, the phase difference between V and I is so device ‘X’ may be an inductor (L) or capacitor (C) but since current (graph C) leads the voltage (graph B), device is capacitor.
For an ideal conductor, connected across a sinusoidal ac voltage source. State which one of the following quantity is zero :
(i) Instantaneous power
(ii) Average power over full cycle of the ac voltage source.
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(a) 1.7 A
(b) 2.05 A
(c) 2.5 A
(d) 25.1 A
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(a) we close the switch
(b) open the switch
(c) increasing the resistance
(d) decreasing the resistance
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(i) the frequency of the source.
(ii) the rms current through the resistor.
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