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 worksheet Practise 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

A proton moves at 1.5 × 10⁵ m/s perpendicular to a uniform magnetic field of 0.05 T. Find the magnitude of the magnetic force F on it.

|q| = 1.602 × 10⁻¹⁹ Cv = 1.5 × 10⁵ m/sB = 0.05 Tθ = 90°

F = fN

2.Easy

A proton moves at 6 × 10⁵ m/s perpendicular to a uniform magnetic field of 0.8 T. Find the magnitude of the magnetic force F on it.

|q| = 1.602 × 10⁻¹⁹ Cv = 6 × 10⁵ m/sB = 0.8 Tθ = 90°

F = fN

3.Medium

Two long parallel wires 12 cm apart carry currents of 15 A and 25 A in the same direction. Find the magnitude of the magnetic flux density B at point P, halfway between them.

I₁ = 15 AI₂ = 25 Ad = 12 cmμ₀ = 4π × 10⁻⁷ T·m/A

B = µT

4.Medium

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

I: up the pageB: out of the page

1up the page
2to the right
3down the page
4to the left

5.Hard

Two coils with self-inductances of 20 mH and 50 mH have a coupling coefficient of 0.8. The current in the first coil changes at 20 A/s. Find the emf ε induced in the second coil.

L₁ = 20 mHL₂ = 50 mHk = 0.8di/dt = 20 A/s

ε = V

6.Hard

In a velocity selector, crossed fields E = 1 × 10⁴ V/m and B = 0.5 T let only ions of one speed pass straight through. Find that speed v.

E = 1 × 10⁴ V/mB₁ = 0.5 T

v = m/s

Answer key

1. F = 1.202 fN
2. F = 76.9 fN
3. B = 33.33 µT
4. to the right
5. ε = 0.506 V
6. v = 20000 m/s

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