IB Physics-Topic#1 Uncertainty-Paper 2 -Qc#8-A magnetized needle is oscillating on a string

A magnetized needle is oscillating on a string about a vertical axis in a horizontal magnetic field B. The time for 10 oscillations is recorded for different values of B. The graph shows the variation with B of the time for 10 oscillations together with the uncertainties in the time measurements. The uncertainty in B is negligible.
a. Draw on the graph the line of best fit for the data.
b. Write down the time taken for one oscillation when B = 0.005 T with its absolute uncertainty.
c. A student forms a hypothesis that the period of one oscillation P is given by: P=K/√B
where K is a constant.
Determine the value of K using the point for which B = 0.005 T.
State the unit of K.
e. The student plots a graph to show how P2 varies with 1/B for the data.
Sketch the shape of the expected line of best fit on the axes below assuming that the relationship P=K/√B is verified. You do not have to put numbers on the axes.
f. State how the value of K can be obtained from the graph.
State the uncertainty in K to an appropriate number of significant figures.
Topic#1 Uncertainty and measurements-Paper#2 Playlist