NASSER VOCATIONAL NV Number: . . . . . . . . . . . . . . . . . .
TRAINING CENTRE Name: . . . . . . . . . . . . . . . . . . . . . .
Class: . . . . . . . . . . . . . . . . . . . . . . .
Date: . . . . . . . . . . . . . . . . Time: 45 Min Total Marks: . . . . . . . . . . / 20
Course: PHY201 Lab-4: Charging and discharging of capacitors Unit: Capacitors
Introduction:
RC circuit is a circuit comprises of
resistor and capacitor. The capacitor
charges through the resistor and gets full
depending on its capacitance in a certain
time called time constant.
Time constant: The time constant is defined
as the time it takes the capacitor to reach
63% of the maximum or fall 37% of the
minimum possible voltage or current. After
two times constants the circuit has reached
86% of the maximum, after five times
constants it nearly reaches 100% of the
maximum.
𝜏 = 𝑅𝐶
Example:
If R = 2200 and C = 1000f
Then the time constant = 2200 x 1000 x 10-6 = 2.2 second.
That is, in 2.2 seconds the capacitor will charge 63%
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Q1. Find the Time constant for the given RC circuit.
Experiment:
Materials: Power supply, Capacitor, Resistor, Alligator clips, Multimeter, Stopwatch.
Procedures:
a) Set up an RC circuit as shown in the circuit
diagram.
b) Charge the capacitor for one minute and take the
voltage for every 5 seconds interval.
c) Discharge the capacitor for one minute and take
again the voltage for every 5 seconds interval.
d) Record the data using table for charging and
discharging. Graph the data being tabulated.
R= _______________ C = ________________ Time constant = R x C = _______________
Time (s) Vc Vc
Charging Discharging
Result: _______________________________________________________________________________
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