Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET2024PhysicsAlternating CurrentActual

The amplitude of the charge oscillating in a circuit decreases exponentially as Q=Q₀ e^ -R t 2 L , where Q₀ is the charge at t=0 ~s . The time at which charge amplitude decreases to 0.50 Q₀ is nearly: [Given that R=1.5 , L=12 mH , (2)=0.693 ]

Options

  1. A19.01 ms
  2. B11.09 ms
  3. C19.01 s
  4. D11.09 s

Correct answer

B. 11.09 ms

Step-by-step solution

Given Q=Q₀ e^ -R t / 2 L R=1.5 , L=12 mH , In (2)=0.693Q=0.5 Q₀, t= ? 0.5 Q₀=Q₀ e^ -R t / 2 L 1 2 =e^ -R t / 2 L Taking log on both sides ( 1 2 )= e^ -R t / 2 L 2= R t 2 L t= 2 L In 2 R = 2 12 10⁻³ 0.693 1.5 t=11.09 ~ms

Practice Alternating Current on Quantrex Academy →

More from Alternating Current

A step down transformer connected to an a.c. mains of 220 V is made to operate at 5.5 V, 44 W lamp. The current in the primary circuit is (Ignore power losses) 2026Which phasor diagram represents LCR circuit at resonance? 2026For an R-L series circuit, the power factor is 3 2 , for R-L frequency f Hz. If the frequency doubles, the new power factor will be 2026In an AC circuit, the current is I = 100 (5t) A. The value of I_ rms is 2026The ratio of power factor of purely resistive circuit to purely reactive circuit is ( 0^ = 1 and 90^ = 0 ) 2026In an LCR series circuit, at resonance, 2026In an AC circuit, E and I are given by E = 150 (150t) V and I = 150 (150t + 3 ) A. The power dissipated in the circuit is (60)^ = 1/2 2026A series LCR circuit is connected across a source E of e.m.f. E=15 (50 t- 3 ) . The current from the supply is I=5 (50 t+ 6 ) . The impedance of the circuit and the phase differenc 2026 Full Alternating Current list All NEET PYQs