In an experiment to study the relationship between the potential difference across a resistor and the current through it, a student recorded the following observations:

Find in which one of the above sets of readings the trend is different from others and must be rejected. Calculate the mean value of resistance of the resistor based on the remaining sets of readings.

Question

In an experiment to study the relationship between the potential difference across a resistor and the current through it, a student recorded the following observations:

Find in which one of the above sets of readings the trend is different from others and must be rejected. Calculate the mean value of resistance of the resistor based on the remaining sets of readings.

Philoid · Accepted Answer

By Ohm’s Law

Case 1:

Resistance(R) =

Case 2:

Resistance(R) =

Case 3:

Resistance(R) =

Case 4:

Resistance(R) =

Case 5:

Resistance(R) =

According to the Ohm’s Law the ratio of the current to the potential difference is always constant (here it is 25). But as we can see in Case 3 the ratio is 3 Ohm while in all other cases it is 25 Ohm.

∴ The trend where Potential Difference is 4.5 V and the current is 0.15 A is different.

Mean Value Of resistance =

= 25 Ohm.

Mean value of resistance is 25 Ohm.