• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Investigation of factors affecting the capacitance of a parallel plate capacitor using electrometer

Extracts from this document...

Introduction

881799.doc        p./

School

Class (No.)

                        (      )

Name

Subject

AL Practical Physics

Date

Mark

C9   Investigation of factors affecting the capacitance of a parallel plate capacitor using electrometer

Procedure

A.        Relationship between charge and p.d. in capacitor

7.        Touch the upper plate with the screened wire of the electrometer to transfer the charge from the parallel plate capacitor to the electrometer. Record the reading of the milliammeter , which represents the charge stored (Q) in the internal capacitor.

9.        Repeat steps 6 to 8 with the other values of voltage outputs (V) of the HT supply in steps of 5 V. Tabulate the results.

Voltage (V) / V

5

10

15

20

25

30

35

Charge (Q) / × 10−8 C

0.19

0.36

0.50

0.70

0.93

1.05

1.24

...read more.

Middle


B.        Factors affecting the capacitance

12.        Repeat steps 6 to 8 with different numbers of spacers (n) between the metal plates. Tabulate the results. Find the reciprocal of the number of spacers (1/n).

No. of spacers (n)

1

2

3

4

5

6

7

1/n

1.00

0.50

0.33

0.25

0.20

0.17

0.14

Charge (Q) / × 10−8 C

1.00

0.50

0.29

0.25

0.12

0.06

0.04

13.        Repeat steps 6 to 8 with different overlapping areas (A) between the

...read more.

Conclusion

Relative permittivity of polythene image01.png

4.        State the sources of error and suggest improvements for this experiment.

(a) Avoid touching the metal plates with an earth hand.

(b) Use screened cable to prevent charge leakage.

(c) The sensitivity of the electrometer may drift after using for a long time, so it is

necessary to work through the whole experiment quickly.

(d) Clean the metal plates with methylated spirit, in order to remove the stray resistance

due to grease and dirt on the plates.

(e) Stray capacitance between the metal plates and the bench may also give experimental

errors.

New Way Physics for Advanced Level                © Manhattan Press 2005

...read more.

This student written piece of work is one of many that can be found in our AS and A Level Electrical & Thermal Physics section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Electrical & Thermal Physics essays

  1. Peer reviewed

    Experiment: Decay of Charge in a Capacitor

    4 star(s)

    E. Error Analysis The time constant ? is estimated by calculating the slope of graph. We try to estimate the error of ? by considering ?lnI and ?t between the data set I = 35 and I = 5.

  2. Investigating the Capacitance of a Parallel-Plate.

    The battery box contains 4 batteries, which allows us to change the electromotive force (e.m.f.) in our investigations on the relationships between e.m.f. and current. The voltmeter measures the exact potential difference (p.d.) delivered by the batteries. The resistance substitution box allows us to adjust the resistance.

  1. Plotting the decay curve of charge in a capacitor

    When we compare the Q-t graph with the I-t graph, we can see that their shape are very similar, this can prove that the charge Q remaining in the capacitor at any time is directly proportional to the current I.

  2. A2 Viscosity investigation

    Radius2 (m2) Distance Travelled(m) Time taken (s) Average Velocity (ms-1) 1 2 3 899x10 203 x10 60x10 7.72 8.14 8.96 71.8x10 +or-4.8x10 634x10 101 x10 60 x10 11.14 12.01 16.73 45.1x10 +or-9.2x10 316x10 25.4 x10 60 x10 24.75 23.97 26.47 23.9x10 +or-1.2x10 199x10 9.80 x10 60 x10 55.09 55.67 56.07

  1. Investigating the Smoothing Effect of a Capacitor on a Resistive Load

    V and C, as shown by the equation: V= I Cf Where we can see that V? 1 provided that I and f remain constant. This can be verified if the graph of 1 against the ripple voltage V takes the form of y=mx i.e.

  2. Investigating the factors affecting the size of current flowing through a length of resistivity ...

    Using the formula?? = ((V/I) x A)/l, and the values V=3.0V, A=0.000064m2, and??= 40m?m, we can predict the current values for different length values: PREDICTED VALUES Cross-sectional area, 0.000064m2 Resistivity, 40 micro ohm meters Length experiment Voltage , 3V Length of putty(l)

  1. Investigating the factors that affect the conductance of a solution

    Replicate the experiment again but this time with sulphuric acid. Making sure all the process is repeated. Modifications to experimental method following trial. In my I found that it was very hard to heat the solution to a certain temperature because during heating the temperature rise was very rapid and did not allow enough time to take accurate readings.

  2. Investigating the capacitance of a parallel report

    When a dielectric is placed between charged plates, the polarization of the medium produces an electric field opposing the field of the charges on the plate. As the capacitance is inversely proportional to the electric field between the plates, the presence of the dielectric reduces the effective electric field, he capacitance of the parallel plate is increased.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work