- #1
Barclay
- 208
- 1
The high school textbook I’m reading says this:
Statement A
“Many household appliances contain an electrically heated resistor. A resistor is a device that opposes the flow of current and as it does this, heat energy is produced. E.g. electric kettles, electric fires, light bulbs.
If we touch the electric flex/cord attached to any of these electric heaters when it’s switched on, we will notice that the flex is either at room temperature or slightly warm to touch. The electric current is increasing the temperature of the heater, by giving energy, but is not having the same effect on the flex.
This is because the heater has higher resistance, to make it difficult for the charge to flow through it. The flex contains copper wires to feed the electricity to and from the heater. Copper has a very low resistance".Then it goes on to say this which is opposite to the statement made above:
Statement B
“If two heaters are each connected to the mains power, the one with lower resistance will allow more current to flow, and will become hotter than the other one”.
Above it said that copper has lower resistance than the heater so does not heat up compared to the heater. Yet in statement B it says that the heater with the lower resistance will heat up more.
Then the section end with this statement that I don’t understand so please help here too:
Statement C
“This is why it’s so important that the live wire and the neutral wire in the flex don’t touch. If they do touch, they make a very low resistance circuit; the flex may burst into flames if the correct fuse is not fitted to break the circuit”.
Thank you
Statement A
“Many household appliances contain an electrically heated resistor. A resistor is a device that opposes the flow of current and as it does this, heat energy is produced. E.g. electric kettles, electric fires, light bulbs.
If we touch the electric flex/cord attached to any of these electric heaters when it’s switched on, we will notice that the flex is either at room temperature or slightly warm to touch. The electric current is increasing the temperature of the heater, by giving energy, but is not having the same effect on the flex.
This is because the heater has higher resistance, to make it difficult for the charge to flow through it. The flex contains copper wires to feed the electricity to and from the heater. Copper has a very low resistance".Then it goes on to say this which is opposite to the statement made above:
Statement B
“If two heaters are each connected to the mains power, the one with lower resistance will allow more current to flow, and will become hotter than the other one”.
Above it said that copper has lower resistance than the heater so does not heat up compared to the heater. Yet in statement B it says that the heater with the lower resistance will heat up more.
Then the section end with this statement that I don’t understand so please help here too:
Statement C
“This is why it’s so important that the live wire and the neutral wire in the flex don’t touch. If they do touch, they make a very low resistance circuit; the flex may burst into flames if the correct fuse is not fitted to break the circuit”.
Thank you