Alternating Current PYQs Set 8 (PDF)

Set 8 of 9 · Questions 211-240 of 244

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Mere Teacher · Previous Year Questions NEET Physics · Alternating Current · Set 8 (Q211-240)
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211. $The net impedance of circuit (as shown in figure) will be [NEET 2023]$ (1) $15Ω$ (2) $55 Ω$ (3) $25Ω$ (4) $102 Ω$ 212. $As per the given graph, choose the correct representation for curve A and curve B {Where X_{C} = Reactance or pure capacitive circuit connected with A.C. source X_{L} = Reactance of pure inductive circuit connected with A.C. source R = Impedance of pure resistive circuit connected with A.C. source Z = Impedance of the LCR series circuit}$ (1) $A = X_{C}, B = R$ (2) $A = X_{L}, B = R$ (3) $A = X_{L}, B = Z$ (4) $A = X_{C}, B = X_{L}$ 213. $Figure shows a circuit that contains three identical resistors with resistance R = 9.0Ω each, two identical inductors with inductance L = 2.0 mH each, and an ideal battery with emf ϵ = 18 V . The current i through the battery just after the switch closed is [NEET 2011]$ (1) $2 mA$ (2) $0.2 A$ (3) $4 A$ (4) $0 A$ 214. $The angular frequency of alternating current in a L - C - R circuit is 100 rad / s . The components connected areshown in the figure. Find the value of inductance of the coil and capacity of condenser.$ (1) $0.8 H and 250 μF$ (2) $0.8 H and 150 μF$ (3) $1.33 H and 250 μF$ (4) $1.33 H and 150 μF$ 215. $Find the mutual inductance in the arrangement, when a small circular loop of wire of radius ‘R’ is placed inside a large square loop of wire of side L (L >> R). The loops are coplanar and their centers coincide:$ (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) $M = \frac{2 μ _{0} R}{L ^{2}}$ 216. $Primary coil of a transformer is connected to 220 V ac. Primary and secondary turns of the transforms are 100 and 10 respectively. Secondary coil of transformer is connected to two series resistance shown in shown in figure. The output voltage (V_{0}) is:$ (1) $7 V$ (2) $15 V$ (3) $44 V$ (4) $22 V$ 217. $An inductor of inductance L, a capacitor of capacitance C and a resistor of resistance R are connected in series to an ac source. The quality factor of the circuit is$ (1) $\frac{L}{C R ^{2}}$ (2) $\frac{LR ^{2}}{C}$ (3) $\frac{LC}{R ^{2}}$ (4) $\frac{L ^{2} C}{R}$ 218. $For the series LCR circuit connected with 220 V, 50 Hz a.c source as shown in the figure, the power factor is \frac{α}{10} . The value of α is____.$ (1) $10$ (2) $4$ (3) $6$ (4) $8$ 219. $An inductor 20 mH, a capacitor 50 µF and a resistor. 40Ω are connected in series across a source of emf V = 10 sin 340t. The power loss in A.C. circuit is$ (1) $0.89 W$ (2) $0.51 W$ (3) $0.67W$ (4) $0.76W$ 220. $In the given circuit the AC source has ω = 100 r ad s^{- 1} . Considering the inductor and capacitor to be ideal, what will be the current I flowing through the circuit?$ (1) $5.9A$ (2) $4.24A$ (3) $0.94A$ (4) $6A$ 221. $A 10Ω resistance is connected across 220V-50Hz AC supply. The time taken by the current to change from its maximum value to the rms value is:$ (1) $2.5ms$ (2) $1.5ms$ (3) $3.0ms$ (4) $4.5ms$ 222. $A 10 μF capacitor is connected to a 210 V, 50 Hz source as shown in figure. The peak current in the circuit is nearly (π = 3.14) [NEET 2024]$ (1) $0.58 A$ (2) $0.93 A$ (3) $1.20 A$ (4) $0.35 A$ 223. $The current (i) at time t = 0 and t = \infty respectively for the given circuit is:$ (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) $\frac{10 E}{33}, \frac{5 E}{18}$ 224. $The L-C-R circuit shown below is driven by an ideal AC voltage source. At frequency f = \frac{1}{2 π LC}, choose the correct statement.$ (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) $The current through R depends only on the value of R and not L and C .$ 225. $The value of alternating emf E in the given circuit will be$ (1) $100 V$ (2) $20 V$ (3) $220 V$ (4) $140 V$ 226. $In a series resonant LCR circuit, the voltage across R is 100 V and the value of R = 1000 Ω . The capacitance of the capacitor is 2 \times 1 0^{- 6} F; angular frequency of AC is 200 rad s^{- 1} . Then the P.D. across the inductance coil is$ (1) $100 V$ (2) $40 V$ (3) $250 V$ (4) $400 V$ 227. $The electric current in the circuit is given as i = i_{0} (t / T) . The r.m.s current for the period t = 0 to t = T is ____ .$ (1) $i_{o}$ (2) $\frac{i _{0}}{6}$ (3) $\frac{i _{0}}{3}$ (4) $\frac{i _{0}}{2}$ 228. $A transformer works on the principle of$ (1) $self-induction$ (2) $electrical inertia$ (3) $magnetic effect of electric current$ (4) $mutual induction$ 229. $When an inductor of inductance \frac{6}{π} H, a capacitor of capacitance \frac{50}{π} μF and resistor of resistance R are connected in series with an AC supply of rms voltage 220 V and frequency 50 Hz, the rms current through the circuit is 440 mA . Match the inductive reactance, XL the capacitive reactance, XC the resistance R and the impedance Z of the circuit given in List-I with the corresponding values given in List-II. LIST-I (A) XL (B) XC (C) R (D) Z LIST-II (I) 200 Ω (II) 300 Ω (III) 500 Ω (IV) 600 Ω$ (1) $(A) - (IV), (B) - (II), (C) - (I), (D) - (III)$ (2) $(A) - (IV), (B) - (III), (C) - (I), (D) - (II)$ (3) $(A) - (IV), (B) - (I), (C) - (II), (D) - (III)$ (4) $(A) - (I), (B) - (IV), (C) - (III), (D) - (II)$ 230. $AC voltage V (t) = 20 sin Ω t of frequency 50Hz is applied to a parallel plate capacitor. The separation between the plates is 2mm and the area is 1 m^{2} . The amplitude of the oscillating displacement current for the applied AC voltage is ___ [Take ϵ_{0} = 8.85 \times 1 0^{- 12} F / m]$ (1) $21.14 μA$ (2) $83.37 μA$ (3) $27.79 μA$ (4) $55.58 μA$ 231. $What happens to the inductive reactance and the current in a purely inductive circuit if the frequency is halved?$ (1) $Both, inductive reactance and current will be halved.$ (2) $Inductive reactance will be halved and current will be doubled.$ (3) $Inductive reactance will be doubled and current will be halved.$ (4) $Both, inducting reactance and current will be doubled.$ 232. $In series LCR circuit at resonance, the phase difference between voltage and current is$ (1) $zero$ (2) $π$ (3) $π /4$ (4) $π /2$ 233. $Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Choke coil is simply a coil having a large inductance but a small resistance. Choke coils are used with fluorescent mercury-tube fittings. If household electric power is directly connected to a mercury tube, the tube will be damaged. Reason (R): By using the choke coil, the voltage across the tube is reduced by a factor \frac{R}{R ^{2} + ω ^{2} L ^{2}}, where ω is frequency of the supply across resistor R and inductor L. If the choke coil were not used, the voltage across the resistor would be the same as the applied voltage. choose the most appropriate answer from the options given below:$ (1) $(A) is true but (R) is false$ (2) $Both (A) and (R) are true and (R) is the correct explanation of (A)$ (3) $(A) is false but (R) is true$ (4) $Both (A) and (R) are true but (R) is not the correct explanation of (A)$ 234. $The rms value of current in a 50 Hz AC circuit is 6 A . The average value of AC current over a cycle is$ (1) $62$ (2) $\frac{3}{π 2}$ (3) $Zero$ (4) $\frac{6}{π 2}$ 235. $In a series LCR resonance circuit, if we change the resistance only, from a lower to higher value:$ (1) $The bandwidth of resonance circuit will increase.$ (2) $The resonance frequency will increase.$ (3) $The quality factor will increase.$ (4) $The quality factor and the resonance frequency will remain constant.$ 236. $An alternating voltage source V = 260 sin (628t) is connected across a pure inductor of 5 mH. Inductive reactance in the circuit is:$ (1) $3.14 Ω$ (2) $6 28 Ω$ (3) $0.5 Ω$ (4) $0.318 Ω$ 237. $An electric heater rated 220 V and 550 W is connected to A.C. mains. The current drawn by it is$ (1) $0.8 A$ (2) $2.5 A$ (3) $0.4 A$ (4) $1.25 A$ 238. $In an ac circuit, an inductor, a capacitor and a resistor are connected in series with X_{L} = R = X_{C} Impedance of this circuit is:$ (1) $2 R^{2}$ (2) $Zero$ (3) $R$ (4) $R 2$ 239. $Match List-I with List II List I (A) Phase difference between current and voltage in a purely resistive AC circuit (B) Phase difference between current and voltage in a pure inductive AC circuit (C) Phase difference between current and voltage in a pure capacitive AC circuit (D) Phase difference between current and voltage in an LCR series circuit List II (I) π 2; current leads voltage (II) Zero (III) π 2; current lags voltage (IV) tan^{- 1} (\frac{X _{C} - X _{L}}{R})$ (1) $(A) - (I), (B) - (III), (C) - (IV), (D) - (II)$ (2) $(A) - (II), (B) - (IV), (C) - (III), (D) - (I)$ (3) $(A) - (II), (B) - (III), (C) - (IV), (D) - (I)$ (4) $(A) - (II), (B) - (III), (C) - (I), (D) - (IV)$ 240. $In a circuit consisting of a capacitance and a generator with alternating emf E_{g} = E_{g_{0}} sin ω t, V_{C} and I_{C} are the voltage and current. Correct phasor diagram for such circuit is:$ (1) (2) (3) (4)