English

Define Capacitive reactance.

Advertisements
Advertisements

Question

Define Capacitive reactance.

Definition
Advertisements

Solution

The effective resistance offered by the capacitor is called capacitive reactance (ΧC).

`Χ_C = 1/omega_C`

`= 1/(2 pi fC)`

shaalaa.com
  Is there an error in this question or solution?
Chapter 13: AC Circuits - Very Short Answer

RELATED QUESTIONS

Show that the current leads the voltage in phase by π/2 in an AC circuit containing an ideal capacitor ?


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?


Is energy produced when a transformer steps up the voltage?


A capacitor acts as an infinite resistance for ______.


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 i1 cos [(100 π s−1)t + φ1) + i2 cos [(500π s−1)t + ϕ2]. So,


The peak voltage of a 220 V AC source is


The AC voltage across a resistance can be measured using


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.


Compare resistance and reactance.


Average power supplied to a capacitor over one complete cycle is ______.


If circuit containing capacitance only, the current ______.


A.C. power is transmitted from a power house at a high voltage as ______.


The frequency of A.C. mains in India is ______.

The electric mains supply in our homes and offices is a voltage that varies like a sine function with time such a voltage is called ... A... and the current driven by it in a circuit is called the ... B... Here, A and B refer to ______.

Of the following about capacitive reactance which is correct?

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.


When an AC voltage of 220 V is applied to the capacitor C ______.

  1. the maximum voltage between plates is 220 V.
  2. the current is in phase with the applied voltage.
  3. the charge on the plates is in phase with the applied voltage.
  4. power delivered to the capacitor is zero.

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.

  1. Which curve shows power consumption over a full cycle?
  2. What is the average power consumption over a cycle?
  3. Identify the device ‘X’.


Explain why the reactance provided by a capacitor to an alternating current decreases with increasing frequency.


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 a.c. source generating a voltage ε = ε0 sin ωt is connected to a capacitor of capacitance C. Find the expression for the current I flowing through it. Plot a graph of ε and I versus ωt to show that the current is ahead of the voltage by π/2.


A resistor of 50 Ω, a capacitor of `(25/pi)` µF and an inductor of `(4/pi)` H are connected in series across an ac source whose voltage (in volts) is given by V = 70 sin (100 πt). Calculate:

  1. the net reactance of the circuit
  2. the impedance of the circuit
  3. the effective value of current in the circuit.

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 ______.


When an AC voltage of 220 V is applied to the capacitor C ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×