Answer :
(a) The applied potential difference (V), as it is controlled and varied during the experiment.
(b) The best fit line is typically a straight line that best represents the relationship between these variables.
(c) The resistance of the specimen is approximately 45.13 ohms.
(a) Dependent and Independent Variables:
Independent variable: The applied potential difference (V), as it is controlled and varied during the experiment.
Dependent variable: The current (I), as it depends on the applied potential difference according to Ohm's Law.
(b) To draw the "best fit" line, you can plot the values of voltage (V) on the x-axis and current (I) on the y-axis. The best fit line is typically a straight line that best represents the relationship between these variables.
(c) To find the resistance, we calculate the ratio of voltage to current for each observation. Taking the average of these values gives the best estimate for the resistance.
Here are the calculations for each observation:
R = 30.5 / 0.49 ≈ 62.24 Ω
R = 40.0 / 0.90 ≈ 44.44 Ω
R = 50.1 / 1.57 ≈ 31.92 Ω
R = 59.5 / 1.57 ≈ 37.94 Ω
R = 70.3 / 1.57 ≈ 44.76 Ω
R = 80.0 / 1.80 ≈ 44.44 Ω
R = 90.0 / 2.00 ≈ 45.00 Ω
Taking the average:
R ≈ (62.24 + 44.44 + 31.92 + 37.94 + 44.76 + 44.44 + 45.00) / 7
≈ 45.13 Ω.
Complete question
In an experiment to verify Ohm's Law, given by the equation V=IR, where V is the applied potential difference, I is the current, and R is the resistance, the following observations were recorded:
Voltage (V) 30.5 40.0 50.1 59.5 70.3 80.0 90.0
Current (I) 0.49 0.90 1.20 1.57 1.57 1.80 2.00
(a) Which is the dependent variable and which is the independent variable?
(b) From the set of observations, draw the 'best-fit' line for the data.
(c) Find the slope of the line and use it to deduce the resistance (R) of the specimen.
