1.Easy
Two point charges of −2 µC and −4 µC are 6 cm apart. Find the magnitude of the electric force F between them. Use k = 8.99 × 10⁹ N·m²/C².
q1 = −2 µCq2 = −4 µCr = 6 cm
F = N
Coulomb’s law & electric fields worksheet with answers
2.Easy
Two point charges of −8 µC and −4 µC are 25 cm apart. Find the magnitude of the electric force F between them. Use k = 8.99 × 10⁹ N·m²/C².
q1 = −8 µCq2 = −4 µCr = 25 cm
F = N
3.Medium
A charge of +2 µC and a charge of −4 µC are 60 cm apart. Point P lies on the line between them, 30 cm from the first charge. Find the magnitude of the electric field E at P.
q1 = +2 µCq2 = −4 µCr1 = 30 cmr2 = 30 cm
E = N/C
4.Medium
A charge of +10 µC and a charge of −2 µC are 60 cm apart. Point P lies on the line between them, 30 cm from the first charge. Find the magnitude of the electric field E at P.
q1 = +10 µCq2 = −2 µCr1 = 30 cmr2 = 30 cm
E = N/C
5.Hard
Three positive point charges sit at the corners of a right triangle: q₃ = 5 µC is at the right-angle corner, q₁ = 3 µC is 4 cm from it along one side and q₂ = 10 µC is 3 cm from it along the other side. Find the magnitude of the net electric force F on q₃.
q1 = 3 µCq2 = 10 µCq3 = 5 µCr13 = 4 cmr23 = 3 cm
F = N
6.Hard
Two identical small balls, each of mass 10 g, hang from the same point on insulating threads 100 cm long. They are given equal charges and each thread settles at 8° 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 = 10 gL = 100 cmθ = 8°g = 9.81 m/s²
q = nC
Answer key
- 1. F = 19.98 N
- 2. F = 4.603 N
- 3. E = 599333 N/C
- 4. E = 1.199 × 10⁶ N/C
- 5. F = 506.5 N
- 6. q = 344.7 nC
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