Magnetic fields & induction worksheet with answers

Free printable Magnetic fields & induction worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

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1.Easy
+v = 1.5 × 10⁶ m/sB = 0.8 T

A proton moves at 1.5 × 10⁶ m/s at an angle of 30° to a uniform magnetic field of 0.8 T. Find the magnitude of the magnetic force F on it.

|q| = 1.602 × 10⁻¹⁹ Cv = 1.5 × 10⁶ m/sB = 0.8 Tθ = 30°
F = fN
2.Easy
+v = 2.5 × 10⁶ m/sB = 0.2 T

An alpha particle moves at 2.5 × 10⁶ m/s at an angle of 45° to a uniform magnetic field of 0.2 T. Find the magnitude of the magnetic force F on it.

|q| = 3.204 × 10⁻¹⁹ Cv = 2.5 × 10⁶ m/sB = 0.2 Tθ = 45°
F = fN
3.Medium
+v = 1.5 × 10⁶ m/sr = ?B = 0.8 T

A proton moves at 1.5 × 10⁶ m/s perpendicular to a uniform magnetic field of 0.8 T. Find the radius r of its circular path.

m = 1.673 × 10⁻²⁷ kg|q| = 1.602 × 10⁻¹⁹ Cv = 1.5 × 10⁶ m/sB = 0.8 T
r = cm
4.Medium
+v = 1 × 10⁵ m/sr = 0.2592 cmB = ?

An alpha particle moving at 1 × 10⁵ m/s enters a uniform magnetic field at right angles and moves on a circle of radius 0.2592 cm. Find the magnetic flux density B.

m = 6.645 × 10⁻²⁷ kg|q| = 3.204 × 10⁻¹⁹ Cv = 1 × 10⁵ m/sr = 0.2592 cm
B = T
5.Hard
l = 15 cmN = 500, ⌀ 2 cm

A long air-core solenoid has 500 turns, a length of 15 cm and a diameter of 2 cm. Find its self-inductance L.

N = 500l = 15 cm⌀ = 2 cmμ₀ = 4π × 10⁻⁷ T·m/A
L = µH
6.Hard
L = 5 mH0 → 2 A

The current in a 5 mH inductor changes steadily from 0 A to 2 A in 2 ms. Find the magnitude of the self-induced emf ε.

L = 5 mH0 A → 2 AΔt = 2 ms
ε = V

Answer key

  1. 1. F = 96.12 fN
  2. 2. F = 113.3 fN
  3. 3. r = 1.958 cm
  4. 4. B = 0.8001 T
  5. 5. L = 658 µH
  6. 6. ε = 5 V

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