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.

New worksheetPractise online with hints

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
+v = 2 × 10⁶ m/sB = 0.02 T

An alpha particle moves at 2 × 10⁶ m/s at an angle of 45° to a uniform magnetic field of 0.02 T. Find the magnitude of the magnetic force F on it.

|q| = 3.204 × 10⁻¹⁹ Cv = 2 × 10⁶ m/sB = 0.02 Tθ = 45°
F = fN
2.Easy
nB20°20 cm × 30 cmB = 0.2 T

A rectangular loop of 20 cm by 30 cm lies in a uniform magnetic field of 0.2 T. The field makes an angle of 20° with the normal of the loop. Find the magnetic flux Φ through the loop.

B = 0.2 TA = 20 cm × 30 cm20° to the normal
Φ = mWb
3.Medium
+v = 3 × 10⁵ m/sr = 0.2089 cmB = ?

A proton moving at 3 × 10⁵ m/s enters a uniform magnetic field at right angles and moves on a circle of radius 0.2089 cm. Find the magnetic flux density B.

m = 1.673 × 10⁻²⁷ kg|q| = 1.602 × 10⁻¹⁹ Cv = 3 × 10⁵ m/sr = 0.2089 cm
B = T
4.Medium
IBF = ?

A wire carries a current to the right through a uniform magnetic field pointing into the page. Click the direction of the magnetic force on the wire.

I: to the rightB: into the page
  1. 1up the page
  2. 2to the right
  3. 3down the page
  4. 4to the left
5.Hard
N1​ = 800, l = 20 cm500 A/sN2​ = 20Mε = ?

A short coil of 20 turns is wound tightly round the middle of a long solenoid of 800 turns, length 20 cm and diameter 5 cm. The current in the solenoid changes at 500 A/s. Find the emf ε induced in the short coil.

N1 = 800N2 = 20l = 20 cm⌀ = 5 cmdi/dt = 500 A/sμ₀ = 4π × 10⁻⁷ T·m/A
ε = mV
6.Hard
Bn = 1800 rpm10 cm × 15 cmN = 20B = 0.2 T

A coil of 20 turns, 10 cm × 15 cm, rotates at 1800 rpm in a uniform field of 0.2 T about an axis perpendicular to the field. Find the rms value Erms of the emf.

N = 20A = 10 cm × 15 cmB = 0.2 Tn = 1800 rpm
Erms = V

Answer key

  1. 1. F = 9.062 fN
  2. 2. Φ = 11.28 mWb
  3. 3. B = 1.5 T
  4. 4. up the page
  5. 5. ε = 98.7 mV
  6. 6. Erms = 7.997 V

Full step-by-step solutions: practise this topic on examproblems.com.