An ac source of angular frequency ???? is fed across a resistor ???? and a capctior ???? in series. The current registered is ????. If the frequency of source is changed to ????/3 (maintaining the same voltage), the current in the circuit is found to be halved. Calculate the ratio of reactance to resistance at the original frequency ????
An ac source of angular frequency ???? is fed across a resistor ???? and a capctior ???? in series. The current registered is ????. If the frequency of source is changed to ????/3 (maintaining the same voltage), the current in the circuit is found to be halved. Calculate the ratio of reactance to resistance at the original frequency ????
Voltage V and current i in AC circuit are given by V = 50 sin(50t) volt; i = 50 sin(50t + π/3) mA. The power dissipated in circuit is
Voltage V and current i in AC circuit are given by V = 50 sin(50t) volt; i = 50 sin(50t + π/3) mA. The power dissipated in circuit is
A virtual current of 4???? and 50 ???????? flows in an ac circuit containing a coil. The power consumed in the coil is 240 ????. If the virtual voltage across the coil is 100 ???? its inductance will be
A virtual current of 4???? and 50 ???????? flows in an ac circuit containing a coil. The power consumed in the coil is 240 ????. If the virtual voltage across the coil is 100 ???? its inductance will be
R/L has the dimensions to
R/L has the dimensions to
A resistor of ???? = 6Ω, an inductor of L = 1 H and a capacitor of ???? = 17.36 μF are connected in series with an AC source. Find the Q - factor.
A resistor of ???? = 6Ω, an inductor of L = 1 H and a capacitor of ???? = 17.36 μF are connected in series with an AC source. Find the Q - factor.
The natural frequency (????₀) of oscillations in L - C circuit is given by
The natural frequency (????₀) of oscillations in L - C circuit is given by
In the circuit shown below, the key K is closed at t = 0. The current through the battery is
In the circuit shown below, the key K is closed at t = 0. The current through the battery is
The power factor of an AC circuit having resistance R and inductance L (connected in series) and an angular velocity ???? is
The power factor of an AC circuit having resistance R and inductance L (connected in series) and an angular velocity ???? is
The primary winding of a transformer has 200 turns and its secondary winding has 50 turns. If the current in the secondary winding is 40 A, the current in the primary is
The primary winding of a transformer has 200 turns and its secondary winding has 50 turns. If the current in the secondary winding is 40 A, the current in the primary is
The peak value of an alternating current is 5 A and its frequency is 60 Hz. Find its rms value and time taken to reach the peak value of current starting from zero.
The peak value of an alternating current is 5 A and its frequency is 60 Hz. Find its rms value and time taken to reach the peak value of current starting from zero.
The resistance of an R-L circuit is 10 Ω. An emf ????₀ applied across the circuit at ???? = 20 rad s⁻¹. If the current in the circuit is i₀/√2, what is the value of L?
The resistance of an R-L circuit is 10 Ω. An emf ????₀ applied across the circuit at ???? = 20 rad s⁻¹. If the current in the circuit is i₀/√2, what is the value of L?
The coefficient of induction of a choke coil is 0.1???? and resistance is 12Ω. If it is connected to an alternating current source of frequency 60 ????????, then power factor will be
The coefficient of induction of a choke coil is 0.1???? and resistance is 12Ω. If it is connected to an alternating current source of frequency 60 ????????, then power factor will be
The process by which ac is converted into dc is known as
The process by which ac is converted into dc is known as
Which one of the following curves represents the variation of impedance (????) with frequency ???? in series ???????????? circuit
Which one of the following curves represents the variation of impedance (????) with frequency ???? in series ???????????? circuit
A uniformly wound solenoidal coil of self inductance 1.8 × 10⁻⁴ H and resistance 6 Ω is broken up into two identical coils. These identical coils are then connected in parallel across a 12 V battery of negligible resistance. The time constant of the current in the circuit and the steady state current through battery is
A uniformly wound solenoidal coil of self inductance 1.8 × 10⁻⁴ H and resistance 6 Ω is broken up into two identical coils. These identical coils are then connected in parallel across a 12 V battery of negligible resistance. The time constant of the current in the circuit and the steady state current through battery is
An ???????????? series circuit is at resonance. Then
An ???????????? series circuit is at resonance. Then
In a circuit, the current lags behind the voltage by a phase difference of ????/2, the circuit will contain which of the following?
In a circuit, the current lags behind the voltage by a phase difference of ????/2, the circuit will contain which of the following?
A coil of wire of certain radius has 100 turns and a self inductance of 15 mH. The self inductance of a second similar coil of 500 turns will be
A coil of wire of certain radius has 100 turns and a self inductance of 15 mH. The self inductance of a second similar coil of 500 turns will be
An inductor (L = 100 mH), a resistor (???? = 100 Ω) and a battery (E = 100 V) are initially connected in series as shown in figure. After a long time the battery is disconnected after short circuiting the points A and B. The current in the circuit 1 ms after the short circuit is
An inductor (L = 100 mH), a resistor (???? = 100 Ω) and a battery (E = 100 V) are initially connected in series as shown in figure. After a long time the battery is disconnected after short circuiting the points A and B. The current in the circuit 1 ms after the short circuit is
The number of turns in a secondary coil is twice the number of turns in primary. A leclanche cell of 1.5 V is connected across the primary. The voltage across secondary is
The number of turns in a secondary coil is twice the number of turns in primary. A leclanche cell of 1.5 V is connected across the primary. The voltage across secondary is
Voltage and current in an ac circuit are given by V = 5 sin(100πt − π/6) and I = 4 sin(100πt + π/6)
Voltage and current in an ac circuit are given by V = 5 sin(100πt − π/6) and I = 4 sin(100πt + π/6)
In an ???????????? series resonant circuit which one of the following cannot be the expression for the Q-factor
In an ???????????? series resonant circuit which one of the following cannot be the expression for the Q-factor
Power dissipated in an ???????????? series circuit connected to an a.c. source of ???????????? ???? is
Power dissipated in an ???????????? series circuit connected to an a.c. source of ???????????? ???? is
An inductor is connected to an AC source. When compared to voltage , the current in the lead wires
An inductor is connected to an AC source. When compared to voltage , the current in the lead wires
When the rate of change of current is unity, induced emf is equal to
When the rate of change of current is unity, induced emf is equal to
A resistor 30 Ω, inductor of reactance 10 Ω and capacitor of reactance 10 Ω are connected in series to an AC voltage source ???? = 300√2 sin(????????). The current in the circuit is
A resistor 30 Ω, inductor of reactance 10 Ω and capacitor of reactance 10 Ω are connected in series to an AC voltage source ???? = 300√2 sin(????????). The current in the circuit is
The frequency for which a 5 ???????? capacitor has a reactance of 1/1000 ????ℎ???? is given by
The frequency for which a 5 ???????? capacitor has a reactance of 1/1000 ????ℎ???? is given by
The initial phase angle for ???? = 10 sin ???????? + 8 cos ???????? is
The initial phase angle for ???? = 10 sin ???????? + 8 cos ???????? is
An alternating current of frequency ‘????’ is flowing in a circuit containing a resistance ???? and a choke ???? in series. The impedance of this circuit is
An alternating current of frequency ‘????’ is flowing in a circuit containing a resistance ???? and a choke ???? in series. The impedance of this circuit is
In a circuit, the value of the alternating current is measured by hot wire ammeter as 10 ????????????????????????. Its peak value will be
In a circuit, the value of the alternating current is measured by hot wire ammeter as 10 ????????????????????????. Its peak value will be
An ac supply gives 30 ???? ????. ????. ????. which passes through a 10 Ω resistance. The power dissipated in it is
An ac supply gives 30 ???? ????. ????. ????. which passes through a 10 Ω resistance. The power dissipated in it is
The power factor of good choke coil is
The power factor of good choke coil is
The phase angle between ????.m.f. and current in ???????????? series as circuit is
The phase angle between ????.m.f. and current in ???????????? series as circuit is
When a DC voltage of 200 V is applied to a coil of self-inductance (2√3/π)H, a current of 1 A flows through it. But by replacing DC source with AC source of 200 V, the current in the coil is reduced to 0.5 A. Then the frequency of AC supply is
When a DC voltage of 200 V is applied to a coil of self-inductance (2√3/π)H, a current of 1 A flows through it. But by replacing DC source with AC source of 200 V, the current in the coil is reduced to 0.5 A. Then the frequency of AC supply is
In an ideal transformer, the voltage is stepped down from 11 kV to 220 V. If the primary current be 100 A, the current in the secondary should be
In an ideal transformer, the voltage is stepped down from 11 kV to 220 V. If the primary current be 100 A, the current in the secondary should be
A square loop of side a placed in the same plane as a long straight wire carrying a current ????. The centre of the loop is at a distance r from the wire, where ???? >> ????, figure. The loop is moved away from the wire with a constant velocity ????. The induced emf in the loop is
A square loop of side a placed in the same plane as a long straight wire carrying a current ????. The centre of the loop is at a distance r from the wire, where ???? >> ????, figure. The loop is moved away from the wire with a constant velocity ????. The induced emf in the loop is
A coil is wound on a core of rectangular cross-section. If all the linear dimensions of core are increased by a factor 2 and number of turns per unit length of coil remains same, the self-inductance increases by a factor of
A coil is wound on a core of rectangular cross-section. If all the linear dimensions of core are increased by a factor 2 and number of turns per unit length of coil remains same, the self-inductance increases by a factor of
A lamp consumes only 50% of peak power in an a.c. circuit. What is the phase difference between the applied voltage and the circuit current
A lamp consumes only 50% of peak power in an a.c. circuit. What is the phase difference between the applied voltage and the circuit current
In an electrical circuit ????, ????, ???? and an a.c. voltage source are all connected in series. When ???? is removed from the circuit, the phase difference between the voltage and the current in the circuit is ????/3. If instead, ???? is removed from the circuit, the phase difference is again ????/3. The power factor of the circuit is
In an electrical circuit ????, ????, ???? and an a.c. voltage source are all connected in series. When ???? is removed from the circuit, the phase difference between the voltage and the current in the circuit is ????/3. If instead, ???? is removed from the circuit, the phase difference is again ????/3. The power factor of the circuit is
An alternating voltage is connected in series with a resistance ???? and an inductance ????. If the potential drop across the resistance is 200 ???? and across the inductance is 150 ????, then the applied voltage is
An alternating voltage is connected in series with a resistance ???? and an inductance ????. If the potential drop across the resistance is 200 ???? and across the inductance is 150 ????, then the applied voltage is
In a series ???????????? circuit, operated with an ac of angular frequency ????, the total impedance is
In a series ???????????? circuit, operated with an ac of angular frequency ????, the total impedance is
A vertical ring of radius r and resistance R falls vertically. It is in contact with two vertical rails which are joined at the top, figure. The rails are without friction and resistance. There is a horizontal uniform magnetic field of magnitude B perpendicular to the plane of the ring and the rails. When the speed of the ring is ????, the current is the section ???????? is
A vertical ring of radius r and resistance R falls vertically. It is in contact with two vertical rails which are joined at the top, figure. The rails are without friction and resistance. There is a horizontal uniform magnetic field of magnitude B perpendicular to the plane of the ring and the rails. When the speed of the ring is ????, the current is the section ???????? is
The voltage of domestic ac is 220 ????????????????. What does the represent
The voltage of domestic ac is 220 ????????????????. What does the represent
If an 8 Ω resistance and 6 Ω reactance are present in an ac series circuit then the impedance of the circuit will be
If an 8 Ω resistance and 6 Ω reactance are present in an ac series circuit then the impedance of the circuit will be
The frequency of an alternating voltage is 50 ????????????????????????/???????????? and its amplitude is 120????. Then the ????. ????. ????. value of voltage is
The frequency of an alternating voltage is 50 ????????????????????????/???????????? and its amplitude is 120????. Then the ????. ????. ????. value of voltage is