Break circuits F uses are used to break circuits if the current passing through it is TOO LARGE that...
6
ses are used to break circuits break circuits if the current passin ough it is TOO LARGE that may probably cause damage the appliances.
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Transcript of Break circuits F uses are used to break circuits if the current passing through it is TOO LARGE that...
Fuses are used to break circuitsbreak circuits if the current passing
through it is TOO LARGE that may probably cause damages to the appliances.
Typical fuse ratings :0.1 A, 0.5 A, 1 A, 3 A, 5A, 13 A, 15 A, 30A, etc.
* If the current in the circuit is greater than the fuse rating, the fuse breaks the circuit then.
* Heater (220V, 2200 W)Operating current or max. current = P / V = 2200 / 220= 10 A
Which fuse rating should be chosen in order to protect the heater?A. 5A B. 10A C. 13A D. 15A
* e.g. Operating current (max. current) Fuse rating chosen0.25 A0.5 A2.5 A3 A3.5A 5A
1A1A3A5A
Circuit Breaker
Electricity Meter / Kilowatt-hour meter (kWh meter)
1 kWh =
* kWh : unit of electricity
* 1 kWh = 1 unit
= (1000 W) (60 x 60 s)
= 3600 000 J
(1 kW) (1 hr)
UnitsUnits consumedconsumed
Amountcharged forelectricity
The HongKongElectric Co. Ltd香港電燈有限公司
Name & AddressName & Address
China Light and PowerHong Kong Ltd中華電力有限公司
Total units consumed= 713
For first 400 units,$0.862 per unit.
Others : $0.932 per unit
Total amountcharged for electricity= $ 344.80 + $291.72= $ 636.52
Average cost of electricity= $ 636.52 / 713= $ 0.893
Other charges
