Concepts Of Physics MCQ Edition [Volume 2]
- Exam
- Concepts Of Physics MCQ Edition [Volume 2]
- Subject
- Physics
- Chapter
- Electric Current in Conductors
Concepts Of Physics MCQ Edition [Volume 2] · Physics · Electric Current in Conductors
A 100 capacitor is joined to a 24 V battery via a 1.0 M resistor....
A capacitor is joined to a battery via a resistor. Which of the following best describes the qualitative graph between current and time for the first minutes?
Options
- AA constant horizontal line at .
- BA linear decrease starting from and reaching zero.
- CAn exponentially growing curve starting from zero and approaching .
- DAn exponentially decaying curve starting from and approaching zero.
Correct answer
D. An exponentially decaying curve starting from and approaching zero.
Step-by-step solution
The given circuit is an RC charging circuit.
The time constant of the circuit is given by .
Substituting the given values:
The initial current in the circuit at is:
The current in an RC circuit during charging varies with time according to the equation:
This equation represents an exponentially decaying curve. At , the current is , and as time progresses, it exponentially approaches zero.
For a duration of minutes (, which is ), the current will have decayed to a value very close to zero. Thus, the graph is an exponentially decaying curve starting from and approaching zero.
The time constant of the circuit is given by .
Substituting the given values:
The initial current in the circuit at is:
The current in an RC circuit during charging varies with time according to the equation:
This equation represents an exponentially decaying curve. At , the current is , and as time progresses, it exponentially approaches zero.
For a duration of minutes (, which is ), the current will have decayed to a value very close to zero. Thus, the graph is an exponentially decaying curve starting from and approaching zero.