1.Easy
A proton (charge 1.602 × 10⁻¹⁹ C, mass 1.673 × 10⁻²⁷ kg) is in a uniform electric field of 3000 N/C. Ignoring gravity, find the magnitude of its acceleration a.
E = 3000 N/C|q| = 1.602 × 10⁻¹⁹ Cm = 1.673 × 10⁻²⁷ kg
a = m/s²
Coulomb’s law & electric fields worksheet with answers
2.Easy
Two point charges of +6 µC and −1 µC are 30 cm apart. Find the magnitude of the electric force F between them. Use k = 8.99 × 10⁹ N·m²/C².
q1 = +6 µCq2 = −1 µCr = 30 cm
F = N
3.Medium
Two identical small metal spheres carry charges of −3 µC and +4 µC. They are touched together and then put back 5 cm apart. Find the magnitude of the force F between them now. Use k = 8.99 × 10⁹ N·m²/C².
q1 = −3 µCq2 = +4 µCr = 5 cm
F = N
4.Medium
A charge of +1 µC and a charge of −3 µC are 20 cm apart. Point P lies on the line between them, 5 cm from the first charge. Find the magnitude of the electric field E at P.
q1 = +1 µCq2 = −3 µCr1 = 5 cmr2 = 15 cm
E = N/C
5.Hard
Two identical small balls, each of mass 3 g, hang from the same point on insulating threads 20 cm long. They are given equal charges and each thread settles at 5° from the vertical. Use g = 9.81 m/s². Find the charge q on each ball in nC. Use k = 8.99 × 10⁹ N·m²/C².
m = 3 gL = 20 cmθ = 5°g = 9.81 m/s²
q = nC
6.Hard
Two identical small balls, each of mass 2 g, hang from the same point on insulating threads 80 cm long. They are given equal charges and each thread settles at 15° from the vertical. Use g = 9.81 m/s². Find the charge q on each ball in nC. Use k = 8.99 × 10⁹ N·m²/C².
m = 2 gL = 80 cmθ = 15°g = 9.81 m/s²
q = nC
Answer key
- 1. a = 2.873 × 10¹¹ m/s²
- 2. F = 0.5993 N
- 3. F = 0.899 N
- 4. E = 4.795 × 10⁶ N/C
- 5. q = 18.66 nC
- 6. q = 316.7 nC
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