Advertisements
Advertisements
Question
A capacitor acts as an infinite resistance for ______.
Options
DC
AC
DC as well as AC
neither AC nor DC
Advertisements
Solution
A capacitor acts as an infinite resistance for DC.
APPEARS IN
RELATED QUESTIONS
When an AC source is connected to a capacitor, there is a steady-state current in the circuit. Does it mean that the charges jump from one plate to the other to complete the circuit?
A current i1 = i0 sin ωt passes through a resistor of resistance R. How much thermal energy is produced in one time period? A current i2 = −i0 sin ωt passes through the resistor. How much thermal energy is produced in one time period? If i1 and i2 both pass through the resistor simultaneously, how much thermal energy is produced? Is the principle of superposition obeyed in this case?
Is energy produced when a transformer steps up the voltage?
The peak voltage of a 220 V AC source is
An AC source is rated 220 V, 50 Hz. The average voltage is calculated in a time interval of 0.01 s. It
The dielectric strength of air is 3.0 × 106 V/m. A parallel-plate air-capacitor has area 20 cm2 and plate separation 0.10 mm. Find the maximum rms voltage of an AC source that can be safely connected to this capacitor.
A transformer has 50 turns in the primary and 100 in the secondary. If the primary is connected to a 220 V DC supply, what will be the voltage across the secondary?
A device Y is connected across an AC source of emf e = e0 sin ωt. The current through Y is given as i = i0 sin (ωt + π/2).
- Identify the device Y and write the expression for its reactance.
- Draw graphs showing a variation of emf and current with time over one cycle of AC for Y.
- How does the reactance of the device Y vary with the frequency of the AC? Show graphically.
- Draw the phasor diagram for device Y.
Average power supplied to a capacitor over one complete cycle is ______.
If circuit containing capacitance only, the current ______.
A capacitor has capacitance C and reactance X, if capacitance and frequency become double, then reactance will be ______.
An alternating current of 1.5 mA and angular frequency 300 rad/sec flows through a 10 k Ω resistor and a 0.50 µF capacitor in series. Find the rms voltage across the capacitor and impedance of the circuit.
A device ‘X’ is connected to an a.c source. The variation of voltage, current and power in one complete cycle is shown in figure.
- Which curve shows power consumption over a full cycle?
- What is the average power consumption over a cycle?
- Identify the device ‘X’.

In the LCR circuit shown in figure, the ac driving voltage is v = vm sin ωt.
- Write down the equation of motion for q (t).
- At t = t0, the voltage source stops and R is short circuited. Now write down how much energy is stored in each of L and C.
- Describe subsequent motion of charges.

A 40 µF capacitor is connected to a 200 V. 50 Hz ac supply. The rms value of the current on the circuit is, nearly ______.
In an ac circuit an alternating voltage e = 200\[\sqrt 2\] sin100t volts is connected to capacitor of capacity 1 µF. The r.m.s. value of the current in the circuit is ______.
