Date | May 2018 | Marks available | 1 | Reference code | 18M.3.SL.TZ1.1 |
Level | Standard level | Paper | Paper 3 | Time zone | 1 |
Command term | State | Question number | 1 | Adapted from | N/A |
Question
A magnetized needle is oscillating on a string about a vertical axis in a horizontal magneticfield 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.
Draw on the graph the line of best fit for the data.
Write down the time taken for one oscillation when B = 0.005 T with its absolute uncertainty.
A student forms a hypothesis that the period of one oscillation P is given by:
where K is a constant.
Determine the value of K using the point for which B = 0.005 T.
State the uncertainty in K to an appropriate number of significant figures.
State the unit of K.
The student plots a graph to show how P2 varies with for the data.
Sketch the shape of the expected line of best fit on the axes below assuming that the relationship is verified. You do not have to put numbers on the axes.
State how the value of K can be obtained from the graph.
Markscheme
smooth line, not kinked, passing through all the error bars.
[1 mark]
0.84 ± 0.03 «s»
Accept any value from the range: 0.81 to 0.87.
Accept uncertainty 0.03 OR 0.025.
[1 mark]
«»
«K =(0.059 ± 0.002)»
uncertainty given to 1sf
Allow ECF [3 max] if 10T is used.
Award [3] for BCA.
[3 marks]
Accept or in words.
[1 mark]
straight AND ascending line
through origin
[2 marks]
[1 mark]