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
nB20°15 cm × 10 cmB = 0.5 T

A rectangular loop of 15 cm by 10 cm lies in a uniform magnetic field of 0.5 T. The field makes an angle of 20° with the normal of the loop. Find the magnetic flux Φ through the loop.

B = 0.5 TA = 15 cm × 10 cm20° to the normal
Φ = mWb
2.Easy
nB60°15 cm × 30 cmB = 0.05 T

A rectangular loop of 15 cm by 30 cm lies in a uniform magnetic field of 0.05 T. The field makes an angle of 60° with the normal of the loop. Find the magnetic flux Φ through the loop.

B = 0.05 TA = 15 cm × 30 cm60° to the normal
Φ = mWb
3.Medium
IBF = ?

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

I: to the leftB: out of the page
  1. 1up the page
  2. 2to the right
  3. 3down the page
  4. 4to the left
4.Medium
+v = 2.5 × 10⁶ m/sr = ?B = 0.5 T

A proton moves at 2.5 × 10⁶ m/s perpendicular to a uniform magnetic field of 0.5 T. Find the radius r of its circular path.

m = 1.673 × 10⁻²⁷ kg|q| = 1.602 × 10⁻¹⁹ Cv = 2.5 × 10⁶ m/sB = 0.5 T
r = cm
5.Hard
V = 500 VB = 0.4 Tr = ?

An alpha particle starts from rest, is accelerated through a potential difference of 500 V and then enters a uniform magnetic field of 0.4 T at right angles. Find the radius r of its path in the field.

m = 6.645 × 10⁻²⁷ kg|q| = 3.204 × 10⁻¹⁹ CV = 500 VB = 0.4 T
r = cm
6.Hard
I = 2 Al = 30 cmN = 800, ⌀ 5 cm

A long air-core solenoid has 800 turns, a length of 30 cm and a diameter of 5 cm. Find the energy W stored in its magnetic field when it carries 2 A.

N = 800l = 30 cm⌀ = 5 cmI = 2 Aμ₀ = 4π × 10⁻⁷ T·m/A
W = mJ

Answer key

  1. 1. Φ = 7.048 mWb
  2. 2. Φ = 1.125 mWb
  3. 3. up the page
  4. 4. r = 5.222 cm
  5. 5. r = 1.139 cm
  6. 6. W = 10.53 mJ

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