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The question "ii. The current flowing through the 8 resistor" is incomplete as it refers to an 8-ohm resistor without a circuit diagram or further context. Please provide the full question or diagram for this part.
Let's proceed with part (c) about the house appliances.
(c) A house has twenty 60W bulbs, two 1000W heater and two 500W security lights. If the appliances are running on a 240V supply calculate
(i) The total power in KW used when all are switched on.
Step 1: Calculate the total power consumed by each type of appliance.
Power from bulbs: Pbulbs=20×60W=1200 W
Power from heaters: Pheaters=2×1000W=2000 W
Power from security lights: Plights=2×500W=1000 W
Step 2: Calculate the total power in Watts.
Ptotal=Pbulbs+Pheaters+Plights
Ptotal=1200W+2000W+1000 W
Ptotal=4200 W
Step 3: Convert the total power from Watts to Kilowatts (KW).
Ptotal(KW)=1000W/KW4200W
Ptotal(KW)=4.2 KW
The total power used is 4.2KW.
(ii) The total current drawn from the mains supply.
Step 1: Use the formula relating power, voltage, and current.
P=VI
Where P is total power, V is voltage, and I is current.
Step 2: Rearrange the formula to solve for current.
I=VP
Step 3: Substitute the total power (in Watts) and the supply voltage.
I=240V4200W
I=17.5 A
The total current drawn from the mains supply is 17.5A.
What's next?