# Mock exam paper D Ordinary Level

Pre-leaving Certificate Examination, 2014

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Physics -Ordinary level

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Time – 3 Hours

Answer three questions from section A and five questions from section B

Section A (120 Marks)

Answer THREE questions from this section.

Each question carries 40 marks.

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1.

A student carried out an experiment to measure the focal length of a converging lens. Firstly the approximate focal length of the lens was established. Then an object was placed outside the focal length and the position of the image found by the no parallax method. The experiment was repeated for a number of values of object distance (u) and the corresponding image distance (v) found.

The results were recorded in the table below

 u/cm 15 25 35 45 55 v/cm 60 23 18.4 16.4 15.3

Describe, with the aid of a clearly labelled diagram, how the image position was found (9)

Indicate the distances u and v on your diagram (4)

Why was it necessary to first find the approximate focal length of the lens (6)

What would happen if the object were placed inside the focal length? (6)

Using all of this data calculate the focal length of the lens (12)

List two sources of error in this experiment (5)

2. Draw a labelled diagram of the equipment you would use in an experiment to measure the velocity of an object (12)

How would you ensure that the object is moving at constant velocity? (6)

State what measurements you would make in this experiment and what equipment you would use to make these measurements (12)

Explain how you would use these measurements to calculate the velocity of the object (10)

3.

In an experiment to measure the specific heat capacity of a liquid, a quantity of liquid was heated in a copper calorimeter. The following measurements were obtained.

Mass of calorimeter =26.5g

Mass of calorimeter and liquid =71.3g

Initial temperature of calorimeter and liquid =18o

Final temperature ...