Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
Concepts Of Physics MCQ Edition [Volume 2]PhysicsAlternating Current

An AC source generating an emf E = E ₀ [ ! ((100 s ⁻¹)t ) + ! ((500 s ⁻¹)t ) ] is connected in series with a resistor and a capacitor. The steady-state current flowing in the circuit is observed to be i = i₁ ! [(100 s ⁻¹)t + ₁ ] + i₂ ! [(500 s ⁻¹)t + ₂ ] .

Options

  1. Ai₁ = i₂
  2. BThe information is insufficient to determine the relationship between i₁ and i₂
  3. Ci₁ > i₂
  4. Di₁ < i₂

Correct answer

D. i₁ < i₂

Step-by-step solution

The given emf has two frequency components: ₁ = 100 s ⁻¹ and ₂ = 500 s ⁻¹ . The impedance of an RC series circuit at an angular frequency is given by Z = R^2 + X_C^2 = R^2 + 1 ^2 C^2 . The amplitude of the steady-state current at frequency is i₀ = E ₀ Z = E ₀ R^2 + 1 ^2 C^2 . Since ₁ 1 ₂^2 C^2 . This implies that the impedance at ₁ is greater than the impedance at ₂ , i.e., Z₁ > Z₂ . Therefore, the current amplitude at ₁ is less than the current amplitude at ₂ , giving i₁ < i₂ .

Practice Alternating Current on Quantrex Academy →

More from Alternating Current

Consider a circuit consisting of a capacitor of capacitance C and a coil with N turns per unit length, cross sectional area S and length d , where d^2 S . There is another coil of 2026An LCR series circuit driven with E_ rms = 90 V at frequency f_d = 30 Hz has resistance R = 80 , , an inductance with inductive reactance X_L = 20.0 , and capacitance with capacitiv 2026A series LCR circuit with R = 20 , L = 1.6 H and C = 40 F is connected to a variable frequency a.c. source. The inductive reactance at resonant frequency is _______ . 2026An a.c. source of angular frequency is connected across a resistor R and a capacitor C in series. The current is observed as I . Now the frequency of the source is changed to /4 , 2026An inductor of 10 mH, capacitor of 0.1 F and a resistor of 100 are connected in series across an a.c power supply 220 V, 70 Hz. The power factor of the given circuit is 0.5 . The d 2026The figure given below shows an LCR series circuit with two switches S₁ and S₂ . When switch S₁ is closed keeping S₂ open, the phase difference ( ) between the current and source v 2026An inductor stores 16 J of magnetic field energy and dissipates 32 W of thermal energy due to its resistance when an a.c. current of 2 A (rms) and frequency 50 Hz flows through it. 2026The electric current in the circuit is given as i=i_ o (t / T) . The r.m.s current for the period t=0 to t=T is _ _ _ _ . 2026 Full Alternating Current list All Concepts Of Physics MCQ Edition [Volume 2] PYQs