Advertisements
Advertisements
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?
Advertisements
उत्तर
The thermal energy produced for an AC circuit in one time period is given by,
H = `Irms^2xx R xx (2pi)/omega`
For current, i1 = i0 sin ωt,
⇒ H = `(i_0^2R)/2 xx (2pi)/omega = (pii_0^2R)/omega`
For current, i2 = −i0 sin ωt,
`Irms = i_0/sqrt(2)`
Hence, the same thermal energy will be produced due to this current.
Since, the direction of i1 and i2 are opposite and their magnitude is same, the net current through the resistor will become zero when both are passed together. Yes, the principle of superposition is obeyed in this case.
APPEARS IN
संबंधित प्रश्न
A 2 µF capacitor, 100 Ω resistor and 8 H inductor are connected in series with an AC source.
(i) What should be the frequency of the source such that current drawn in the circuit is maximum? What is this frequency called?
(ii) If the peak value of e.m.f. of the source is 200 V, find the maximum current.
(iii) Draw a graph showing variation of amplitude of circuit current with changing frequency of applied voltage in a series LRC circuit for two different values of resistance R1 and R2 (R1 > R2).
(iv) Define the term 'Sharpness of Resonance'. Under what condition, does a circuit become more selective?
The peak voltage of a 220 V AC source is
The AC voltage across a resistance can be measured using
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?
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?
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’.
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:
- the net reactance of the circuit
- the impedance of the circuit
- the effective value of current in the circuit.
An AC source is connected to a capacitor C. Due to decrease in its operating frequency ______.
In an alternating current circuit consisting of elements in series, the current increases on increasing the frequency of supply. Which of the following elements are likely to constitute the circuit?
Which relation expresses that the voltage across the capacitor equals the applied voltage?
Which expression gives the capacitor current in terms of peak current \[i_m\]?
What is the capacitive reactance of a capacitor?
What is the average power over one complete cycle for a capacitor connected to an AC source?
What happens when a DC source is connected to a capacitor?
How does the current in a capacitor connected to an AC source compare in phase with the voltage?
How does inserting an iron rod into the inductor affect its inductive reactance?
