Advertisements
Advertisements
प्रश्न
When an AC voltage of 220 V is applied to the capacitor C ______.
- the maximum voltage between plates is 220 V.
- the current is in phase with the applied voltage.
- the charge on the plates is in phase with the applied voltage.
- power delivered to the capacitor is zero.
विकल्प
b and c
a and d
b and d
c and d
Advertisements
उत्तर
c and d
Explanation:
If the alternating voltage is applied to the capacitor, the plate connected to the positive terminal of the source will be at a higher potential and the plate connected to the negative terminal of the source will be at a lower potential. So the plate's capacitor is charged.
Power applied to circuit is `P_(av) = V_(rms) I_(rms) cos phi`
`phi` = 90° for pure capacitor circuit
∴ Pav = Vrms Irms cos 90° = 0.
APPEARS IN
संबंधित प्रश्न
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?
A transformer is designed to convert an AC voltage of 220 V to an AC voltage of 12 V. If the input terminals are connected to a DC voltage of 220 V, the transformer usually burns. Explain.
An AC source producing emf ε = ε0 [cos (100 π s−1)t + cos (500 π s−1)t] is connected in series with a capacitor and a resistor. The steady-state current in the circuit is found to be i = i1 cos [(100 π s−1)t + φ1) + i2 cos [(500π s−1)t + ϕ2]. So,
The AC voltage across a resistance can be measured using
A bulb rated 60 W at 220 V is connected across a household supply of alternating voltage of 220 V. Calculate the maximum instantaneous current through the filament.
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.
Suppose the initial charge on the capacitor is 6 mC. What is the total energy stored in the circuit initially? What is the total energy at later time?
Average power supplied to a capacitor over one complete cycle is ______.
A.C. power is transmitted from a power house at a high voltage as ______.
When an ac voltage of 220 V is applied to the capacitor C, then ______.
A capacitor has capacitance C and reactance X, if capacitance and frequency become double, then reactance will be ______.
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.
An iron cored coil is connected in series with an electric bulb with an AC source as shown in figure. When iron piece is taken out of the coil, the brightness of the bulb will ______.
An AC source is connected to a capacitor C. Due to decrease in its operating frequency ______.
A 10 µF capacitor is connected to a 210 V, 50 Hz source as shown in figure. The peak current in the circuit is nearly ______.
(π = 3.14)
