1.Easy
Two point charges repel each other with a force of 46 N. The first charge is doubled and the distance between the charges is tripled. Find the new force F′.
F = 46 Nq₁′ = 2·q₁r′ = 3·r
F′ = N
Coulomb’s law & electric fields worksheet with answers
2.Easy
Two point charges of −2 µC and −5 µC are 12 cm apart. Find the magnitude of the electric force F between them. Use k = 8.99 × 10⁹ N·m²/C².
q1 = −2 µCq2 = −5 µCr = 12 cm
F = N
3.Medium
A charge of +6 µC and a charge of −2 µC are 60 cm apart. Point P lies on the line between them, 36 cm from the first charge. Find the magnitude of the electric field E at P.
q1 = +6 µCq2 = −2 µCr1 = 36 cmr2 = 24 cm
E = N/C
4.Medium
A charge of +1 µC and a charge of −5 µC are 30 cm apart. Point P lies on the line between them, 18 cm from the first charge. Find the magnitude of the electric field E at P.
q1 = +1 µCq2 = −5 µCr1 = 18 cmr2 = 12 cm
E = N/C
5.Hard
Charges of +8 µC and +8 µC are 20 cm apart. Point P lies 10 cm from the midpoint between them, on the perpendicular bisector. Find the magnitude of the electric field E at P. Use k = 8.99 × 10⁹ N·m²/C².
q1 = +8 µCq2 = +8 µCd = 20 cmh = 10 cm
E = N/C
6.Hard
Three positive point charges sit at the corners of a right triangle: q₃ = 6 µC is at the right-angle corner, q₁ = 3 µC is 8 cm from it along one side and q₂ = 10 µC is 10 cm from it along the other side. Find the magnitude of the net electric force F on q₃.
q1 = 3 µCq2 = 10 µCq3 = 6 µCr13 = 8 cmr23 = 10 cm
F = N
Answer key
- 1. F′ = 10.22 N
- 2. F = 6.243 N
- 3. E = 728356 N/C
- 4. E = 3.399 × 10⁶ N/C
- 5. E = 5.086 × 10⁶ N/C
- 6. F = 59.57 N
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