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
nB53°10 cm × 25 cmB = 0.25 T

A rectangular loop of 10 cm by 25 cm lies in a uniform magnetic field of 0.25 T. The field makes an angle of 53° with the normal of the loop. Find the magnetic flux Φ through the loop.

B = 0.25 TA = 10 cm × 25 cm53° to the normal
Φ = mWb
2.Easy
nB37°15 cm × 10 cmB = 0.1 T

A rectangular loop of 15 cm by 10 cm lies in a uniform magnetic field of 0.1 T. The field makes an angle of 37° with the normal of the loop. Find the magnetic flux Φ through the loop.

B = 0.1 TA = 15 cm × 10 cm37° to the normal
Φ = mWb
3.Medium
+vBF = ?

A proton moves to the left through a uniform magnetic field pointing into the page. Click the direction of the magnetic force on it.

v: to the leftB: into the page
  1. 1up the page
  2. 2to the right
  3. 3down the page
  4. 4to the left
4.Medium
R = 2.5 Ωv = 10 m/sL = 80 cmB = 1 T

A metal rod 80 cm long slides at 10 m/s along two rails in a uniform field of 1 T into the page. The rails are joined by a resistor of 2.5 Ω; the rod and rails have negligible resistance. Find the power P dissipated in the resistor.

B = 1 TL = 80 cmv = 10 m/sR = 2.5 Ω
P = W
5.Hard
I = 3 Al = 50 cmN = 300, ⌀ 1 cm

A long air-core solenoid has 300 turns, a length of 50 cm and a diameter of 1 cm. Find the energy W stored in its magnetic field when it carries 3 A.

N = 300l = 50 cm⌀ = 1 cmI = 3 Aμ₀ = 4π × 10⁻⁷ T·m/A
W = µJ
6.Hard
E = 2 × 10⁴ V/m, B1​ = 0.05 T

In a velocity selector, crossed fields E = 2 × 10⁴ V/m and B = 0.05 T let only ions of one speed pass straight through. Find that speed v.

E = 2 × 10⁴ V/mB1 = 0.05 T
v = m/s

Answer key

  1. 1. Φ = 3.761 mWb
  2. 2. Φ = 1.198 mWb
  3. 3. down the page
  4. 4. P = 25.6 W
  5. 5. W = 79.94 µJ
  6. 6. v = 400000 m/s

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