Question 1.    [1 mark]

An air-filled parallel plate capacitor uses square plates. Each plate has a side of length 14.0 cm. Determine the gap d required to obtain a capacitance of 160 pF.

Use ε₀ = 8.8541878128 × 10⁻¹² F⋅m⁻¹. Neglect fringing fields.

Question 2.    [2 marks]

A circular coil of radius 14.0 cm is on the x-y plane, with the origin at its centre. It has 100 turns and carries a current of 2.5 A. There is no magnetic material near the coil.

1. Determine |B_z(0, 0, 0)|, the magnitude of B_z at the centre of the coil.
2. Determine the positive value of z, for which B_z(0, 0, z) is 0.2 times B_z(0, 0, 0).

Question 3.    [1 mark]

At 20 °C, a metal wire resistor has a resistance of 100 Ω.
The material used for the wire has α = 2.8 × 10⁻³ °C⁻¹.

Determine the temperature if the measured resistance is 102 Ω.

Question 4.    [1 mark]

In the Wheatstone bridge network shown,

V_B = 5 V, R₁ = 87 Ω, R₂ = 114 Ω, R₃ = 100 Ω, and R₄ = 100 Ω.

Determine V_o.