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

A 100 F capacitor is joined to a 24 V battery via a 1.0 M resistor. Which of the following best describes the qualitative graph between charge and time for the first 10 minutes?

Options

  1. AA constant horizontal line at 2400 C .
  2. BAn exponentially decaying curve starting from 2400 C and approaching zero.
  3. CA linear increase starting from zero and reaching 2400 C .
  4. DAn exponentially growing curve starting from zero and approaching 2400 C .

Correct answer

D. An exponentially growing curve starting from zero and approaching 2400 C .

Step-by-step solution

The time constant of the RC circuit is given by = RC = (1.0 10^6 )(100 10⁻⁶ F ) = 100 s . The maximum steady-state charge on the capacitor is Q₀ = CV = (100 F )(24 V ) = 2400 C . The equation for the charge on a charging capacitor as a function of time is q(t) = Q₀ (1 - e^ -t/ ) . This equation represents an exponentially growing curve that starts from zero at t = 0 and asymptotically approaches the maximum charge Q₀ = 2400 C . Since the given time interval is 10 minutes = 600 s = 6 , the capacitor will be nearly f

Practice Electric Current in Conductors on Quantrex Academy →

More from Electric Current in Conductors

The amount of charge passing through a cross-section of a wire in time t is given by Q(t) = At^2 + Bt + C . Determine the dimensional formulae for A , B , and C .A discharge tube carries an electric current of 2.0 A . Determine the amount of charge that passes through a cross-section of the tube in 5 minutes.The current flowing through a wire varies with time according to i = i₀ + t , where i₀ = 10 A and = 4 A s ⁻¹ . Determine the charge that crosses a section of the wire in 10 secondsA copper wire with a cross-section of 1.0 mm ^2 carries a current of 1.0 A . Determine the drift speed of the free electrons in the wire, assuming there is one free electron per atAn electron gun releases 2.0 10¹⁶ electrons per second. Determine the electric current this corresponds to.The amount of charge passing through a cross-section of a wire in time t is Q(t) = At^2 + Bt + C . Assuming the numerical values of A , B , and C in SI units are 5 , 3 , and 1 respA uniform wire having a resistance of 100 is melted and recast into a new wire whose length is double that of the original. What will be the resistance of the new wire?Determine the required length of a copper wire having a cross-sectional area of 0.01 mm ^2 to produce a resistance of 1 k . The resistivity of copper is given as 1.7 10⁻⁸ m . Full Electric Current in Conductors list All Concepts Of Physics MCQ Edition [Volume 2] PYQs