Understanding Uncertainties in Physics

What is the percentage uncertainty of a data point if the absolute uncertainty is 1 volt and the value is 15 volts?

• 5.0%

• 6.7%

• 10.0%

• 7.5%

How do you determine the line of best fit when calculating uncertainties in the gradient?

• It should pass through the origin.

• It should be parallel to the x-axis.

• It should pass through all data points.

• It should have an even spread of points on either side.

What is the rule for drawing the line of worst fit?

• From the top of the top error bar to the bottom of the bottom error bar.

• From the bottom of the bottom error bar to the top of the top error bar.

• From the leftmost to the rightmost data point.

• From the center of the graph to the edge.

How is the percentage uncertainty in the gradient calculated?

• By subtracting the gradient of the line of best fit from the gradient of the line of worst fit, divided by the gradient of the line of best fit, times 100.

• By dividing the absolute uncertainty by the gradient of the line of best fit.

• By multiplying the gradient of the line of best fit by the absolute uncertainty.

• By adding the gradients of the lines of best and worst fit.

Why is it important to understand uncertainties and experimental skills in physics exams?

• They are not relevant to theoretical physics.

• They are only important for lab work.

• They are frequently tested in exams.

• They are only useful for advanced physics courses.