Alternating Current PYQs Set 9 (PDF)

Set 9 of 10 · Questions 241-270 of 290

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Mere Teacher · Previous Year Questions JEE Main Physics · Alternating Current · Set 9 (Q241-270)
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241. $In a series LCR circuit, the inductive reactance (X_{L}) is 10Ω and the capacitive reactance (X_{C}) is 4Ω . Theresistance (R) in the circuit is 6Ω. The power factor of the circuit is:$ (1) $\frac{1}{2}$ (2) $\frac{1}{2 2}$ (3) $\frac{1}{2}$ (4) $\frac{3}{2}$ 242. $An inductor of inductance L, a capacitor of capacitance C and a resistor of resistance R are connected in series to an AC source of potential difference V volts as shown in figure. Potential difference across L, C and R is 40 V, 10 V and 40 V, respectively. The amplitude of current flowing through L - C - R series circuit is 102 A . The impedance of the circuit is [NEET 2021]$ (1) $42 Ω$ (2) $52 Ω$ (3) $4Ω$ (4) $5Ω$ 243. $What will be the reading in the voltmeter and ammeter of the circuit shown?$ (1) $90 V, 2 A$ (2) $0 V, 2 A$ (3) $90 V, 1 A$ (4) $0 V, 1 A$ 244. $A series R - C circuit is connected to an alternating voltage source. Consider two situations(A) When capacitor is air filled.(B) When capacitor is mica filled. Current through resistor is i and voltage across capacitor is V, then$ (1) $V_{A} < V_{B}$ (2) $V_{A} > V_{B}$ (3) $i_{A} > i_{B}$ (4) $V_{A} = V_{B}$ 245. $In the given circuit the peak voltages across C, L and R are 30 V, 110 V and 60 V respectively. The rms value of the applied voltage is$ (1) $70.7 V$ (2) $141 V$ (3) $100 V$ (4) $200 V$ 246. $A branch of a circuit is shown in the figure. If current is decreasing at the rate of 10^{3} As^{- 1}, then the potential difference between A and B is$ (1) $1 V$ (2) $5 V$ (3) $10 V$ (4) $2 V$ 247. $A series AC circuit containing an inductor (20mH), a capacitor (120μF) and resistor (60Ω) is driven by an AC source of 24 V/50 Hz. The energy dissipated in the circuit in 60 s is:$ (1) $5.65\times10² J$ (2) $2.26\times10³ J$ (3) $5.17\times10² J$ (4) $3.39\times10³ J$ 248. $For the given input voltage waveform V_{in} (t), the output voltage waveform V_{0} (t), across the capacitor is correctly depicted by$ (1) (2) (3) (4) 249. $The net impedance of circuit (as shown in figure) will be [NEET 2023]$ (1) $15Ω$ (2) $55 Ω$ (3) $25Ω$ (4) $102 Ω$ 250. $As per the given graph, choose the correct representation for curve A and curve B {Where X_{C} = Reactance or pure capacitive circuit connected with A.C. source X_{L} = Reactance of pure inductive circuit connected with A.C. source R = Impedance of pure resistive circuit connected with A.C. source Z = Impedance of the LCR series circuit}$ (1) $A = X_{C}, B = R$ (2) $A = X_{L}, B = R$ (3) $A = X_{L}, B = Z$ (4) $A = X_{C}, B = X_{L}$ 251. $Figure shows a circuit that contains three identical resistors with resistance R = 9.0Ω each, two identical inductors with inductance L = 2.0 mH each, and an ideal battery with emf ϵ = 18 V . The current i through the battery just after the switch closed is [NEET 2011]$ (1) $2 mA$ (2) $0.2 A$ (3) $4 A$ (4) $0 A$ 252. $The angular frequency of alternating current in a L - C - R circuit is 100 rad / s . The components connected areshown in the figure. Find the value of inductance of the coil and capacity of condenser.$ (1) $0.8 H and 250 μF$ (2) $0.8 H and 150 μF$ (3) $1.33 H and 250 μF$ (4) $1.33 H and 150 μF$ 253. $Find the mutual inductance in the arrangement, when a small circular loop of wire of radius ‘R’ is placed inside a large square loop of wire of side L (L >> R). The loops are coplanar and their centers coincide:$ (1) $M = \frac{2 μ _{0} R ^{2}}{L}$ (2) $M = \frac{2 2 μ _{0} R ^{2}}{L ^{2}}$ (3) $M = \frac{2 2 μ _{0} R ^{2}}{L}$ (4) $M = \frac{2 μ _{0} R}{L ^{2}}$ 254. $Primary coil of a transformer is connected to 220 V ac. Primary and secondary turns of the transforms are 100 and 10 respectively. Secondary coil of transformer is connected to two series resistance shown in shown in figure. The output voltage (V_{0}) is:$ (1) $7 V$ (2) $15 V$ (3) $44 V$ (4) $22 V$ 255. $An inductor of inductance L, a capacitor of capacitance C and a resistor of resistance R are connected in series to an ac source. The quality factor of the circuit is$ (1) $\frac{L}{C R ^{2}}$ (2) $\frac{LR ^{2}}{C}$ (3) $\frac{LC}{R ^{2}}$ (4) $\frac{L ^{2} C}{R}$ 256. $For the series LCR circuit connected with 220 V, 50 Hz a.c source as shown in the figure, the power factor is \frac{α}{10} . The value of α is____.$ (1) $10$ (2) $4$ (3) $6$ (4) $8$ 257. $An inductor 20 mH, a capacitor 50 µF and a resistor. 40Ω are connected in series across a source of emf V = 10 sin 340t. The power loss in A.C. circuit is$ (1) $0.89 W$ (2) $0.51 W$ (3) $0.67W$ (4) $0.76W$ 258. $In the given circuit the AC source has ω = 100 r ad s^{- 1} . Considering the inductor and capacitor to be ideal, what will be the current I flowing through the circuit?$ (1) $5.9A$ (2) $4.24A$ (3) $0.94A$ (4) $6A$ 259. $A 10Ω resistance is connected across 220V-50Hz AC supply. The time taken by the current to change from its maximum value to the rms value is:$ (1) $2.5ms$ (2) $1.5ms$ (3) $3.0ms$ (4) $4.5ms$ 260. $A 10 μF capacitor is connected to a 210 V, 50 Hz source as shown in figure. The peak current in the circuit is nearly (π = 3.14) [NEET 2024]$ (1) $0.58 A$ (2) $0.93 A$ (3) $1.20 A$ (4) $0.35 A$ 261. $The current (i) at time t = 0 and t = \infty respectively for the given circuit is:$ (1) $\frac{18 E}{55}, \frac{5 E}{18}$ (2) $\frac{5 E}{18}, \frac{18 E}{55}$ (3) $\frac{5 E}{18}, \frac{10 E}{33}$ (4) $\frac{10 E}{33}, \frac{5 E}{18}$ 262. $The L-C-R circuit shown below is driven by an ideal AC voltage source. At frequency f = \frac{1}{2 π LC}, choose the correct statement.$ (1) $The current through R is zero.$ (2) $The current through R is infinite.$ (3) $The current through R depends on the value of L and C .$ (4) $The current through R depends only on the value of R and not L and C .$ 263. $The value of alternating emf E in the given circuit will be$ (1) $100 V$ (2) $20 V$ (3) $220 V$ (4) $140 V$ 264. $In a series resonant LCR circuit, the voltage across R is 100 V and the value of R = 1000 Ω . The capacitance of the capacitor is 2 \times 1 0^{- 6} F; angular frequency of AC is 200 rad s^{- 1} . Then the P.D. across the inductance coil is$ (1) $100 V$ (2) $40 V$ (3) $250 V$ (4) $400 V$ 265. $Three identical resistors with resistance R = 12 Ω and two identical inductors with sell inductance L = 5 mH are connected to an ideal battery with emf of 12 V as shown in figure. The current through the battery long after the switch has been closed will be A.$ 266. $At very high frequencies, the effective impedance of the given circuit will be Ω$ 267. $The effective current I in the given circuit at very high frequencies will be A$ 268. $Two circuits are shown in the figure (a) & (b). At a frequency of the average power dissipated in one cycle will be same in both the circuits.$ 269. $In a series LCR circuit, the inductance, capacitance and resistance are L = 100mH, C = 100 μ F and R = 10 Ω respectively. They are connected to an AC source of voltage 220V and frequency of 50 Hz. The approximate value of current in the circuit will be____A.$ 270. $A series LCR circuit is connected to an ac source of 220V, 50Hz. The circuit contain a resistance R = 100 Ω and an inductor of inductive reactance X_{L} = 79.6 Ω . The capacitance of the capacitor needed to maximize the average rate at which energy is supplied will be_________μ F$