Different Type of AC Circuits PYQs: JEE Mains Physics

Showing 1–25 of 25 questions

1. 1. A bulb and a capacitor are connected in series across an AC supply. A dielectric is then placed between the plates of the capacitor. The glow of the bulb: 2024 Hard
2. 2. A coil of negligible resistance is connected in series with \(90 \Omega\) resistor across \(120 \mathrm{~V}, 60 \mathrm{~Hz}\) supply. A voltmeter reads \(36 \mathrm{~V}\) across resistance. Inductance of the coil is _______. 2024 Hard
3. 3. \(AC\) alternating emf \(\mathrm{E}=110 \sqrt{2} \sin 100 \mathrm{t}\) volt is applied to a capacitor of \(2 \mu \mathrm{F}\), the rms value of current in the circuit is _______ \(\mathrm{mA}\). 2024 Hard
4. 4. In an ac circuit, the instantaneous current is zero, when the instantaneous voltage is maximum. In this case, the source may be connected to: \(A\). pure inductor. \(B\). pure capacitor. \(C\). pure resistor. \(D\). combination of an inductor and capacitor. Choose the correct answer from the options given below: 2024 Hard
5. 5. When a coil is connected across a \(20 \mathrm{~V}\) DC supply, it draws a current of \(5 \mathrm{~A}\). When it is connected across \(20 \mathrm{~V}, 50 \mathrm{~Hz}\) AC supply, it draws a current of \(4 \mathrm{~A}\). The self inductance of the coil is _______ \(\mathrm{mH}\). (Take \(\pi=3\) ) 2024 Hard
6. 6. A capacitor of capacitance \(150.0\,\mu F\) is connected to an alternating source of \(emf\) given by \(E =36\) \(\sin (120 \pi t ) V\). The maximum value of current in the circuit is approximately equal to \(......\,A\) 2023 Medium
7. 7. A capacitor of capacitance \(500\,\mu F\) is charged completely using a dc supply of \(100\,V\). It is now connected to an inductor of inductance \(50\,mH\) to form an \(LC\) circuit. The maximum current in \(LC\) circuit will be \(.........A\). 2022 Medium
8. 8. A circuit element \(X\) when connected to an a.c. supply of peak voltage \(100\,V\) gives a peak current of \(5\,A\) which is in phase with the voltage. A second element \(Y\) when connected to the same a.c. supply also gives the same value of peak current which lags behind the voltage by \(\frac{\pi}{2}\). If \(X\) and \(Y\) are connected in series to the same supply, what will be the rms value of the current in ampere? 2022 Medium
9. 9. An alternating \(emf\) \(E =440 \sin 100 \pi t\) is applited to a circuit containing an inductance of \(\frac{\sqrt{2}}{\pi} H\). If an a.c. ammeter is connected in the circuit, its reading will be \(.......A\) 2022 Hard
10. 10. As shown in the figure an inductor of inductance \(200\, mH\) is connected to an \(AC\) source of emf \(220 \,V\) and frequency \(50 \,Hz\). The instantaneous voltage of the source is \(0\, V\) when the peak value of current is \(\frac{\sqrt{a}}{\pi} A\). The value of a is..........
    2022 Medium
11. 11. In a series \(L R\) circuit \(X_{L}=R\) and power factor of the circuit is \(P _{1}\). When capacitor with capacitance \(C\) such that \(X _{ L }= X _{ C }\) is put in series, the power factor becomes \(P_{2}\). The ratio \(\frac{ P _{1}}{ P _{2}}\) is 2022 Medium
12. 12. In a series \(LCR\) circuit, the inductance, capacitance and resistance are \(L =100\, mH , C =100 \mu F\) and \(R =\) \(10 \Omega\) respectively. They are connected to an \(AC\) source of voltage \(220\, V\) and frequency of \(50\, Hz\). The approximate value of current in the circuit will be.....\(A.\)
    2022 Medium
13. 13. The equation of current in a purely inductive circuit is \(5 \sin \left(49 \pi t-30^{\circ}\right)\). If the inductance is \(30\,mH\) then the equation for the voltage across the inductor, will be.\(\left\{\right.\) Let \(\left.\pi=\frac{22}{7}\right\}\) 2022 Medium
14. 14. The rms value of conduction current in a parallel plate capacitor is \(6.9\,\mu\,A\). The capacity of this capacitor, if it is connected to \(230 V\) ac supply with an angular frequency of \(600\,rad / s\), will be \(....\,pF\) 2022 Medium
15. 15. Figure shows a circuit that contains four identical resistors with resistance \(R =2.0\, \Omega,\) two identical inductors with inductance \(L =2.0 \,mH\) and an ideal battery with \(e m f E =9 \,V .\) The current \('i'\) just after the switch \('S'\) is closed will be .... \(A\)
    2021 Hard
16. 16. Two circuit are shown in the figure \((a)\) and \((b).\) At a frequency of \(....\,rad/s\) the average power dissipated in one cycle will be same in both the circuits.
    2021 Hard
17. 17. What happens to the inductive reactance and the current in a purely inductive circuit if the frequency is halved ? 2021 Medium
18. 18. An inductance coil has a reactance of \(100\, \Omega\). When an \(AC\) signal of frequency \(1000\, Hz\) is applied to the coil, the applied voltage leads the current by \(45^{\circ}\). The self- inductance of the coil is 2020 Hard
19. 19. In \(LC\) circuit the inductance \(\mathrm{L}=40\; \mathrm{mH}\) and capacitance \(\mathrm{C}=100\; \mu \mathrm{F} .\) If a voltage \(\mathrm{V}(\mathrm{t})=10 \sin (314 \mathrm{t})\) is applied to the circuit, the current in the circuit is given as  2020 Hard
20. 20. A \(20\, Henry\) inductor coil is connected to a \(10\, ohm\) resistance in series as shown in figure. The time at which rate of dissipation of energy (Joule’s heat) across resistance is equal to the rate at which magnetic energy is stored in the inductor, is
    2019 Hard
21. 21. A circuit connected to an \(ac\) source of \(emf\) \(e = e_0\, sin\, (1000t)\) with \(t\) in seconds, gives a phase difference of \(\frac{\pi }{4}\) between the \(emf\) \(e\) and current \(i\). Which of the following circuits will exhibit this? 2019 Hard
22. 22. Consider the \(LR\) circuit shown in the figure. If the switch \(S\) is closed at \(t = 0\) then the amount of charge that passes through the battery between \(t = 0\) and \(t = \frac{L}{R}\) is
    2019 Hard
23. 23. An arc lamp requires a direct current of \(10\ A\) at \(80\ V\) to function. If it is connected to a \( 220\ V (rms ), 50\ Hz\ AC\) supply, the series inductor needed for it to work is close to : 2016 Medium
24. 24. A sinusoidal voltage \(V(t) = 100\,sin\,(500t)\) is applied across a pure inductance of \(L = 0.02\,H.\) The current through the coil is 2014 Medium
25. 25. In the circuit shown here, the voltage across \(L\) and \(C\) are respectively \(300\, V\) and \(400\, V\). The voltage \(E\) of the ac source is......\(Volt\)
    2013 Easy

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