ENGG 1301 2018-2019 Term 2
Assignment 1
Submission deadline: 5pm, 28 January 2019
Answer all questions. Show all steps of your derivations and reasoning.
Question 1 (10 points)
A force of 500 N exists between two identical point charges separated by a distance of 40 cm,
Calculate the magnitude of the two point charges.
Question 2 (10 points)
An attractive force of 1500 N exists between a +900 nC charge and another charge. The two
charges are separated by 50 mm. What is the magnitude and sign of the other charge?
Question 3 (10 points)
What is the electric flux through a sphere of radius 4m that contains a
a) +50 μC
b) -50 μC
charge at its center?
Question 4 (10 points)
An insulating sphere of radius 2.0 m contains +50 μC of electric charge uniformly distributed
throughout the volume of the sphere.
a) What is the electric field 1.5 m away from the center of the sphere?
b) What is the volume charge density?
c) What is the electric field 3.0 m away from the center of the sphere?
Question 5 (10 points)
The following figure shows a parallel-plate capacitor with a plate area 9.99 cm2 and plate
separation d=4.5 mm. The top half of the gap is filled with material of dielectric constant ε1
= 10.0; the bottom half is filled with material of dielectric constant ε2 = 13.0. What is the
capacitance?
