DP Physics (first assessment 2025)

Question 23M.2.HL.TZ1.7b

[Maximum mark: 4]

23M.2.HL.TZ1.7b

(b)

Just before the loop is about to completely exit the region of magnetic field, the loop moves with constant terminal speed v.

The following data is available:

Determine, in m s⁻¹ the terminal speed v.

[4]

Markscheme

mg = BIL OR I = 0.33 «A» ✓

BvL = IR OR ℰ = 8.25 × 10⁻³ «V» OR ℰ = 0.12v ✓

Combining results to get v = $\frac{m g R}{B^{2} L^{2}}$ ✓

v = « $\frac{0.040 \times 9.81 \times 0.025}{0 . 80^{2} \times 0 . 15^{2}}$ =» 0.068 «m s⁻¹»

Allow ECF between steps if clear work is shown.

Syllabus sections