LEAVING CERTIFICATE EXAMINATION 2004: PHYSICS – HIGHER LEVEL
2004 Question 1
In an experiment to measure the acceleration due to gravity g by a free fall method, a student measured the time t for
an object to fall from rest through a distance s.
This procedure was repeated for a series of values of the distance s.
The table shows the data recorded by the student.
s/cm
30
40
50
60
70
80
90
t/ms
244
291
325
342
371
409
420
(i) Describe, with the aid of a diagram, how the student obtained the data.
(ii) Calculate a value for the acceleration due to gravity g by drawing a suitable graph based on the recorded data.
(iii) Give two precautions that should be taken to ensure a more accurate result.
2004 Question 2
In an experiment to measure the wavelength of monochromatic light, the angle θ between a central bright image (n =
0) and the first and second order images to the left and the right was measured.
A diffraction grating with 500 lines per mm was used.
The table shows the recorded data.
n
2
1
0
1
2
θ /degr ees
36.2
17.1
0
17.2
36.3
(i) Describe, with the aid of a diagram, how the student obtained the data.
(ii) Use all of the data to calculate a value for the wavelength of the light.
(iii) Explain how using a diffraction grating with 100 lines per mm leads to a less accurate result.
(iv) The values for the angles on the left of the central image are smaller than the corresponding ones on the right.
Suggest a possible reason for this.
2004 Question 3
A student investigated the variation of the fundamental frequency f of a stretched string with its length l.
(i) Draw a labelled diagram of the apparatus used in this experiment. Indicate on the
diagram the points between which the length of the wire was measured.
The student drew a graph, as shown, using the data recorded in the experiment, to
illustrate the relationship between the fundamental frequency of the string and its length.
(ii) State this relationship and explain how the graph verifies it.
The student then investigated the variation of the fundamental frequency f of the
stretched string with its tension T.
The length was kept constant throughout this investigation.
(iii) How was the tension measured?
(iv) What relationship did the student discover?
(v) Why was it necessary to keep the length constant?
(vi) How did the student know that the string was vibrating at its fundamental frequency?
2004 Question 4
The following is part of a student’s report of an experiment to measure the resistivity of nichrome wire.
“The resistance and length of the nichrome wire were found. The diameter of the wire was then measured at several
points along its length.”
The following data was recorded.
Resistance of wire = 32.1 Ω
Length of wire = 90.1 cm
Diameter of wire = 0.19 mm, 0.21 mm, 0.20 mm, 0.21 mm, 0.20 mm
(i) Name an instrument to measure the diameter of the wire and describe how it is used.
(ii) Why was the diameter of the wire measured at several points along its length?
(iii) Using the data, calculate a value for the resistivity of nichrome.
(iv) Give two precautions that should be taken when measuring the length of the wire.
