Author Question: Identical point charges (+20 mC) are placed at the corners of an equilateral triangle with sides of ... (Read 173 times)

karen · **on:** Jul 28, 2018

Identical point charges (+20 mC) are placed at the corners of an equilateral triangle with sides of 2.0-m length. How much external energy is required to bring a charge of 45 mC from infinity to the midpoint of one side of the triangle?
a. 26 J
b. 16 J
c. 23 J
d. 21 J
e. 12 J

Question 2

A charge of +3.0 mC is distributed uniformly along the circumference of a circle with a radius of 20 cm. How much external energy is required to bring a charge of 25mC from infinity to the center of the circle?
a. 5.4 J
b. 3.4 J
c. 4.3 J
d. 2.7 J
e. 6.8 J