Chapter 4: Capacitors
Al Shuwaib School
Charge on A Capacitor
Name: AHMED BESTON
Grade 12(A)
Objectives: - To calculate the charge on a capacitor.
- To determine the relationship between the charge and the voltage.
Materials: different sizes parallel plates capacitor, plates stand, voltmeter, power supply (AC & DC), cables
Procedures #1: - (Measuring the charge on a capacitor)
1) Connect the plates as shown in the image above and fix the distance between its plates.
2) Measure the area of the plates then calculate the capacitance on the plates using the formula and
write it down in the table 1 below.
3) Measure the voltage between the plates and note it down in the table 1 below.
4) Calculate the charge on the capacitor using the formula and record it in the table 1.
5) Replace the plates with the other capacitor with same distance in front of you and repeat steps 2,3,
and 4.
Increase the voltage of the battery and observe the value of the charge. Record your data.
6) Calculate the value,
and record the results in data table.
Results:-
Table 1
Capacitor Type
Capacitance
q = C ∆V
(C)
(F)
1. Smaller surface area
4.43X10^-13 F
1.06 pC
2. larger surface area
8.677X10^-13 F
2.08 PC
Procedures #2: - (determine the relationship between the charge and voltage on a capacitor)
7) Connect only one type of capacitor to the circuit (small/ large) and fix the distance between the
plates.
8) Measure the area of the plate then calculate the capacitance using the formula and note it in table
2.
9) Measure the voltage between the plates and note it down in the table 2 below.
10) Calculate the charge on the capacitor using the formula and record it in the table 2.
Increase the voltage of the PS and observe the value of the charge. Record your data.
11) Increase the voltage even more of the PS and observe the value of the charge. Record your data.
12) Write your conclusion about the relationship between the charge and the voltage of a capacitor
in the analyze data part underneath table 2.
Results:-
Table 2
Capacitance –
Voltage
(V)
2.4
(F): ………………………………….
q = C ∆V
(C)
1.06 pC
3.43
1.51 pC
4.45
1.97 pC
6.52
2.89 pC
Analyze data:- What is the relationship between the voltage and the net charge on the plate?
Direct proportional , when the voltage increase the net charge increase .
Graphing: Use your data from table 2 to plot the voltage versus the charge on the graph. (the voltage on x
axis and the charge on y axis)
- Calculate the slope of the resulting line.
4.37x10^-13
- What does the slope represent?
Capacitance
- Compare the value of the slope with the value of capacitance.
The same .