1.Easy
An electron (charge −1.602 × 10⁻¹⁹ C, mass 9.109 × 10⁻³¹ kg) is in a uniform electric field of 600 N/C. Ignoring gravity, find the magnitude of its acceleration a.
E = 600 N/C|q| = 1.602 × 10⁻¹⁹ Cm = 9.109 × 10⁻³¹ kg
a = m/s²
Coulomb’s law & electric fields worksheet with answers
2.Easy
Two point charges repel each other with a force of 10 N. The first charge is tripled and the distance between the charges is doubled. Find the new force F′.
F = 10 Nq₁′ = 3·q₁r′ = 2·r
F′ = N
3.Medium
A charge of +8 µC and a charge of −6 µC are 30 cm apart. Point P lies on the line between them, 22.5 cm from the first charge. Find the magnitude of the electric field E at P.
q1 = +8 µCq2 = −6 µCr1 = 22.5 cmr2 = 7.5 cm
E = N/C
4.Medium
A charge of +4 µC and a charge of −6 µC are 30 cm apart. Point P lies on the line between them, 7.5 cm from the first charge. Find the magnitude of the electric field E at P.
q1 = +4 µCq2 = −6 µCr1 = 7.5 cmr2 = 22.5 cm
E = N/C
5.Hard
Three positive point charges sit at the corners of a right triangle: q₃ = 2 µC is at the right-angle corner, q₁ = 2 µC is 8 cm from it along one side and q₂ = 5 µC is 10 cm from it along the other side. Find the magnitude of the net electric force F on q₃.
q1 = 2 µCq2 = 5 µCq3 = 2 µCr13 = 8 cmr23 = 10 cm
F = N
6.Hard
Three positive point charges sit at the corners of a right triangle: q₃ = 3 µC is at the right-angle corner, q₁ = 3 µC is 4 cm from it along one side and q₂ = 5 µC is 4 cm from it along the other side. Find the magnitude of the net electric force F on q₃.
q1 = 3 µCq2 = 5 µCq3 = 3 µCr13 = 4 cmr23 = 4 cm
F = N
Answer key
- 1. a = 1.055 × 10¹⁴ m/s²
- 2. F′ = 7.5 N
- 3. E = 1.101 × 10⁷ N/C
- 4. E = 7.458 × 10⁶ N/C
- 5. F = 10.6 N
- 6. F = 98.29 N
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