1.Easy
A rectangular loop of 5 cm by 20 cm lies in a uniform magnetic field of 1.2 T. The field makes an angle of 53° with the normal of the loop. Find the magnetic flux Φ through the loop.
B = 1.2 TA = 5 cm × 20 cm53° to the normal
Φ = mWb
Magnetic fields & induction worksheet with answers
2.Easy
An alpha particle moves at 2 × 10⁶ m/s at an angle of 60° to a uniform magnetic field of 1 T. Find the magnitude of the magnetic force F on it.
|q| = 3.204 × 10⁻¹⁹ Cv = 2 × 10⁶ m/sB = 1 Tθ = 60°
F = fN
3.Medium
Two long parallel wires 12 cm apart carry currents of 15 A and 5 A in opposite directions. Find the force per metre of length F/L between them.
I1 = 15 AI2 = 5 Ad = 12 cmμ₀ = 4π × 10⁻⁷ T·m/A
F/L = µN/m
4.Medium
A proton moves down the page through a uniform magnetic field pointing out of the page. Click the direction of the magnetic force on it.
v: down the pageB: out of the page
- 1up the page
- 2to the right
- 3down the page
- 4to the left
5.Hard
A proton starts from rest, is accelerated through a potential difference of 2500 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 = 1.673 × 10⁻²⁷ kg|q| = 1.602 × 10⁻¹⁹ CV = 2500 VB = 0.4 T
r = cm
6.Hard
An alpha particle passes undeflected through a velocity selector with crossed fields E = 4 × 10⁴ V/m and B₁ = 0.5 T. It then enters a second region with only a magnetic field B₂ = 0.25 T, at right angles. Find the radius r of its path there.
E = 4 × 10⁴ V/mB1 = 0.5 TB2 = 0.25 Tm = 6.645 × 10⁻²⁷ kg|q| = 3.204 × 10⁻¹⁹ C
r = cm
Answer key
- 1. Φ = 7.222 mWb
- 2. F = 554.9 fN
- 3. F/L = 125 µN/m
- 4. to the left
- 5. r = 1.807 cm
- 6. r = 0.6637 cm
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