Electric Field

Question 1(Grade 12 SA:Year2010)

Two point charges Q1 and Q2 a distance 4m apart are shown below .The charge on Q1 is -14μC and the charge on Q2 is +20μC.

1.1)            Define the electric field at a point in space.

1.2)            Draw the electric field pattern due to these two charges.

1.3)            Calculate the net electric field at point P situated 2m from Q2.                                                                                                                                                                                                           

Question 2

Two charged metallic plates are placed 15cm apart in vacuum and are kept at a p.d of 450V. An electron is released from rest at a point close to the negative plate .How long it will take to reach the other plate and with what velocity?(Mass of electron = 9.1x 10^-31Kg and charge of electron = 1.6x 10^-19C).