10.1 A simplified sketch of an AC generator is shown below - NSC Physical Sciences - Question 10 - 2016 - Paper 1

When the coil is rotated through 180°, the direction of the current in segment PQ will change from P to Q.

To calculate the resistance (R) of the device, we use Ohm's Law:

$R = \frac{V_{rms}}{I_{rms}}$

Given that the rms voltage (V_{rms}) is 220 V and the rms current (I_{rms}) is 8 A:

$R = \frac{220 V}{8 A} = 27.5 \Omega$

The energy (E) consumed can be calculated using the formula:

$E = P \cdot t$

First, we need to calculate the power (P):

$P = V_{rms} \cdot I_{rms} = 220 V \cdot 8 A = 1760 W$

Now, we convert two hours into seconds:

$t = 2 \cdot 3600 = 7200 s$

Now, substituting the values to find the energy consumed:

$E = 1760 W \cdot 7200 s = 12672000 J$