Question

Briefly describe an example of a possible scientific experiment, and identify both the independent and the dependent variable. please don't hand write the answer.

Answer 1

Experiment: To find the value of unknown resistance in a circuit having a variable voltage source of 0-10V

Aparatus required: Variable Voltage source, Ammeter, Volmeter and resistor of an unknown resistance.

Diagram of the setup

We connect the unknown resistance with the viariable voltage source and connect the ammeter in series with the resistor. We connect the voltmeter parallel with the resistor. The voltmeter will measure the voltage drop across the resistor and the ammeter will read the current passing through the resistor. We slowly increase the voltage of the variable voltage supply in small steps, and measure the voltage drop across the resistor in voltmeter and its corresponding current that flows through the resistor through the ammeter. We then plot the current vs voltage (I in y-axis and potential in x-axis) graph, it will give a straight line and we find out the slope.

We know, V=IR, V=voltage drop across resistor, I is the current passing through the resistor and R is the resistance

thus slope is inverse of resistance

This is how we find the value of unknown resistance

Since as we change the voltage the value of current changes, it means that the current depends on voltage. That means