DP Physics (last assessment 2024)

Question 21N.2.HL.TZ0.3a.i

a.i.

[Maximum mark: 2]

21N.2.HL.TZ0.3a.i

Two equal positive fixed point charges Q = +44 μC and point P are at the vertices of an equilateral triangle of side 0.48 m.

(a.i)

Show that the magnitude of the resultant electric field at P is 3 MN C⁻¹

[2]

Markscheme

«electric field at P from one charge is $\frac{k Q}{r^{2}} =$ » $\frac{8.99 \times 10^{9} \times 44 \times 10^{- 6}}{0 . 48^{2}}$

$1.7168 \times 10^{6}$ «NC⁻¹» ✓

« net field is » $2 \times 1.7168 \times 10^{6} \times \cos 30 ° = 2.97 \times 10^{6}$ «NC⁻¹» ✓

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