Current, Potential difference and Resistance [ Hard]

Question 1

Finish the statements;
An ammeter is connected in a ___ circuit not a ____ circuit
A voltage is connected in a ___ circuit not a ____ circuit
The student made an error by measuring the _____ instead of the __________ when recording IV characteristics.

Answer 1

1.Series, parllel
2.Parallel, series
3. variable resistor, filament lamp

Question 2

Suggest the reasons why the reading of current at all potential difference is differnt to those recorded by another students in class [ This is an IV charcaterstics investigation]

Answer 2

The ammeter and voltmeter had different resistance[1]
One of them did not calculate mean value of current [1]

Question 3

Explain how the shape of the graph that the filament bulb is a non-ohmic conducter[4]

Answer 3

Ohm’s law states that current is proportional to the voltage.
As the potential difference increases so as the current increases.[1]
But at the rate at which the current increases, decreases[1]
This is because the temperature of filament bulb increases as the current increases.[1]
so the resistance increases causing the current to decrease.[1]
Simple form:
At low voltages, the graph starts with a gentle slope (current increases easily).
As voltage increases, the filament heats up, and resistance increases.
This makes the graph curve and flatten out, showing that the current rises more slowly with increasing voltage.

Question 4

Describe the difference between conventional current and electrical flow. [4]

Answer 4

Electron flow is the flow of electrons in a closed circuit[1]
Electrons have a negative charge so they move to postive terminal.[1]
Conventional current is the percieved movement of postive charge[1]
Which moves from toward the negative terminal[1]

Question 5

What is meant by direct potential difference[1]

Answer 5

The direction of potential difference does not change.

Question 6

What is the equation of power?
What is the equation of resistance?
What is the equation of potential differnce
What is the equation of charge flow?

Answer 6

1.P=V×I
2.R= V/I
3.V=I×R
4.Q=I×t
​

V- potential difference,
R= Resistance, I= Current , t = time