P2 Electricity Flashcards
1
Q
Why is it dangerous for a kite to fly next to a power cable?
A
- Electric field strength is very high
- Air becomes ionised, allowing to conduct charge
- Kite conducts charge to person/earth
2
Q
Why do wires of different materials in a power cable have different currents through them?
A
- They all have the same potential difference
-Wires of different materials have different resistances.
-Due to V=IR, and V being constant, the wires with higher resistance will have lower current through them
3
Q
How to calculate total resistance for two resistors in series?
A
R = R1+ R2
4
Q
How to calculate total resistance for two resistors in parallel?
A
The reciprocal of the total resistance is equal to the sum of the reciprocals of the two resistances
1/R = 1/R1 + 1/R2
5
Q
A
