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 = 2 × 10⁵ m/sB = 0.2 T

A proton moves at 2 × 10⁵ m/s at an angle of 30° to a uniform magnetic field of 0.2 T. Find the magnitude of the magnetic force F on it.

|q| = 1.602 × 10⁻¹⁹ Cv = 2 × 10⁵ m/sB = 0.2 Tθ = 30°
F = fN
2.Easy
nB20°5 cm × 25 cmB = 0.05 T

A rectangular loop of 5 cm by 25 cm lies in a uniform magnetic field of 0.05 T. The field makes an angle of 20° with the normal of the loop. Find the magnetic flux Φ through the loop.

B = 0.05 TA = 5 cm × 25 cm20° to the normal
Φ = mWb
3.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
4.Medium
+v = 2.5 × 10⁵ m/sr = 2.611 cmB = ?

A proton moving at 2.5 × 10⁵ m/s enters a uniform magnetic field at right angles and moves on a circle of radius 2.611 cm. Find the magnetic flux density B.

m = 1.673 × 10⁻²⁷ kg|q| = 1.602 × 10⁻¹⁹ Cv = 2.5 × 10⁵ m/sr = 2.611 cm
B = T
5.Hard
Bn = 1800 rpm10 cm × 5 cmN = 200B = 0.4 T

A coil of 200 turns, 10 cm × 5 cm, rotates at 1800 rpm in a uniform field of 0.4 T about an axis perpendicular to the field. Find the peak emf E0.

N = 200A = 10 cm × 5 cmB = 0.4 Tn = 1800 rpm
E0 = V
6.Hard
Bn = 3600 rpm8 cm × 25 cmN = 250B = 0.2 T

A coil of 250 turns, 8 cm × 25 cm, rotates at 3600 rpm in a uniform field of 0.2 T about an axis perpendicular to the field. Find the peak emf E0.

N = 250A = 8 cm × 25 cmB = 0.2 Tn = 3600 rpm
E0 = V

Answer key

  1. 1. F = 3.204 fN
  2. 2. Φ = 0.5873 mWb
  3. 3. counterclockwise
  4. 4. B = 0.09999 T
  5. 5. E0 = 75.4 V
  6. 6. E0 = 377 V

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