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 = 6 × 10⁵ m/sB = 1 T

An electron moves at 6 × 10⁵ m/s at an angle of 60° to a uniform magnetic field of 1 T. Find the magnitude of the magnetic force F on it.

|q| = 1.602 × 10⁻¹⁹ Cv = 6 × 10⁵ m/sB = 1 Tθ = 60°
F = fN
2.Easy
+v = 4 × 10⁶ m/sB = 0.5 T

A proton moves at 4 × 10⁶ m/s at an angle of 30° to a uniform magnetic field of 0.5 T. Find the magnitude of the magnetic force F on it.

|q| = 1.602 × 10⁻¹⁹ Cv = 4 × 10⁶ m/sB = 0.5 Tθ = 30°
F = fN
3.Medium
−v = 1.5 × 10⁶ m/sr = 0.2132 cmB = ?

An electron moving at 1.5 × 10⁶ m/s enters a uniform magnetic field at right angles and moves on a circle of radius 0.2132 cm. Find the magnetic flux density B.

m = 9.109 × 10⁻³¹ kg|q| = 1.602 × 10⁻¹⁹ Cv = 1.5 × 10⁶ m/sr = 0.2132 cm
B = mT
4.Medium
vI = ?

A square loop moves to the right into a region with a uniform magnetic field pointing into the page. Click the direction of the induced current in the loop as seen in the drawing, while the loop is entering the field.

B: into the pageentering the field
  1. 1clockwise
  2. 2counterclockwise
5.Hard
Bn = 600 rpm20 cm × 20 cmN = 100B = 0.3 T

A coil of 100 turns, 20 cm × 20 cm, rotates at 600 rpm in a uniform field of 0.3 T about an axis perpendicular to the field. Find the rms value Erms of the emf.

N = 100A = 20 cm × 20 cmB = 0.3 Tn = 600 rpm
Erms = V
6.Hard
L1​ = 10 mH1000 A/sL2​ = 200 mHk = 0.5ε = ?

Two coils with self-inductances of 10 mH and 200 mH have a coupling coefficient of 0.5. The current in the first coil changes at 1000 A/s. Find the emf ε induced in the second coil.

L1 = 10 mHL2 = 200 mHk = 0.5di/dt = 1000 A/s
ε = V

Answer key

  1. 1. F = 83.24 fN
  2. 2. F = 160.2 fN
  3. 3. B = 4 mT
  4. 4. counterclockwise
  5. 5. Erms = 53.31 V
  6. 6. ε = 22.36 V

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