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Evan Toh
Nov 4, 20241 min read
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Evan Toh
Nov 4, 20241 min read
Overloading of a multi plug resulting in overheating and fire
It fine to use a multiplug as it brings convenience. The problem arises when too many high power appliances are connected and on at the...
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Evan Toh
Nov 3, 20241 min read
Changing a 2 pin-plug to 3 pin-plug
Changing the pin will not change the voltage required by the appliance.
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Evan Toh
Nov 3, 20241 min read
Simple heating element demo
The wire used here is not the typical copper wire. It is nichrome wire which has much higher resistivity compared to copper. Hence, for...
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Evan Toh
Oct 21, 20241 min read
Using P = I^2R and P = V^2/R to explain which component uses the highest power or energy.
Instead of P = IV to explain, it might be easier to explain using P = I^2R when the components are connected in series where current I is...
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Evan Toh
Jan 31, 20241 min read
2021SPp2q8 - Which appliance uses most energy (using P = V^2/R to explain)
Resistors may be connected in series or parallel. When asked which resistor has higher power (hence higher energy), in general we will...
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Evan Toh
Jan 31, 20241 min read
PP2017Q11 Using P=I^2R and P=V^2/R to explain which has higher power
Resistors may be connected in series or parallel. When asked which resistor has higher power (hence higher energy), in general we will...
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Evan Toh
Dec 31, 20231 min read
Why the fuse and switch must be on the live wire?
A common mistake is to state that the reason for switch to be on the live wire is “so that the switch can turn on/off the appliance”....
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Evan Toh
Dec 31, 20231 min read
Why do we need earth wire and fuse?
Simply put, electric appliance can be very simple with just a live wire bring in the current and a neutral wire to bring the current out....
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Evan Toh
Dec 31, 20232 min read
SP N2007 P1 Q16 – Which events will cause the fuse to blow?
An electric cable contains three wires live, neutral and earth. The cable is correctly wired to a plug which contains a 3A fuse. The...
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Evan Toh
Dec 31, 20231 min read
2013SPp1q17 What is the new P when V across resistor is doubled? Similar 2018PPp1q31
Answer: Option C View the videos below to learn how to solve it. There are more than one method. Alternatively, you may put values to...
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Evan Toh
Dec 31, 20231 min read
Function of Fuse
Fuse is a safety feature. In the event of an electrical fault, where there is a short circuit current which exceeds the fuse rating, the...
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Evan Toh
Nov 30, 20231 min read
2007PPP1Q27 brightness of bulb
Solutions: Option B As lamp X is thicker and shorter , these two factors make the resistance of X lower than Y . Recall: Length...
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