Question 2 (References: Example 27.3, Example 28.4, Problem 27.17)
a. Determine the magnitude and direction of the electric field at point P, 20 cm away from
charge Q = +10𝜇𝐶.
Work:
Magnitude: 2.25 x 10 ^6 N/C Direction: Upward
b. Two charges are lying on the horizontal axis and are 0.2m away from each other. The charges
are: 𝑞1 = 20𝜇𝐶 𝑎𝑛𝑑 𝑞2 = −40𝜇𝐶. Determine the magnitude and direction of the force on q1 by q2.
Work:
Magnitude: 180 N
Direction: to the right
c. An electron (q = -1.6 x 10-19 C) is initially at rest. At some time later, the electron accelerates
due to a 5 kV potential. Determine the change in electrical potential energy and final speed of the
electron.
Work:
ΔPE:-8.0 x 10 ^-16 J vf: 4.193 x 10 ^7 m/s
d. Write down three examples of the use of electricity and magnetism in the medical field. For example,
an automated external defibrillator (AED) consists of a capacitor to store electrical energy and electrode
pads to deliver an electrical shock to your heart. As a result, an automated external defibrillator (AED)
with CPR increases the chances of restoring a victim’s heartrate after a sudden cardiac arrest. Use three of
your own examples. There are plenty of examples in chapters 43-44.
Example 1: An example of use of electricity and magnetism in the medical field would be x-ray
equipment and scanners.
Example 2: Another example of use of electricity and magnetism in the medical field would be
electromagnetic therapy. it uses electromagnetic radiation to treat diseases.
Example 3: Another example of use of electricity and magnetism in the medical field is magnetic
resonance imaging which scans the body.