Answer:potential difference is more or less like voltage. Using ohms, V=IR
Where V is Voltage
I is Current =0.4A
R is Resistance=20ohms
V=0.4*20
V=8V
Hence the potential difference will be 8V.
ii) V=0.4*30
V=12V
Explanation:
The voltage of potential difference is directly proportional to the current and the resistance. So if one increase or decrease, it will have impact on the other.
From the calculations, when the resistance increase, the voltage will increase to appreciate the change.
Since steel contains iron (a magnetic metal), the magnets will attract the steel cans since aluminum is not magnetic. This is used to separate the steel cans from the aluminum cans so they can be recycled separately.
