AS 1.2 Measurements & Errors

Question 1 The density of the material of a coil of thin wire is to be found. Which set of instruments could be used to do this most accurately?

• A Metre rule, protractor, spring balance
• B Micrometer, metre rule, top-pan balance
• C Stopwatch, newton-meter, vernier calipers
• D Tape measure, vernier calipers, lever balance

Question 2 The diagram shows part of a thermometer. What is the correct reading on the thermometer and the uncertainty in this reading?

• A 24 ∓ 1
• B 24 ∓ 0.1
• C 24.0 ∓ 0.2
• D 24.0 ∓ 0.5

Question 3 In an experiment to determine the acceleration of free fall using a falling body, what would lead to a value that is too large?

• A air resistance
• B dimensions of the body are too large
• C measured distance longer than true distance
• D measure time longer than true-time

Question 4 The diagram shows the stem of a Celsius thermometer marked to show initial and final temperature values. What is the temperature change expressed to an appropriate number of significant figures?

• A 14⁰ C
• B 20.5⁰ C
• C 21⁰ C
• D 22⁰ C

Question 5 A metre rule is used to measure the length of a piece of wire. It is found to be 70 cm long to the nearest millimetre. How should this result be recorded in a table of results?

• A 0.7 m
• B 0.70 m
• C 0.700 m
• D 0.7000 m

Question 6 The diagrams show digital voltmeter and analogue ammeter readings from a circuit in which electrical heating is occurring. What is the electrical power of the heater?

• A 0.53 W
• B 0.58 W
• C 530 W
• D 580 W

Question 7 An experiment is done to measure the acceleration of free fall of a body from rest. Which measurements are needed?

• A The height of fall and the time of fall
• B The height of fall and the weight of the body
• C The mass of the body and the height of fall
• D The mass of the body and the time of fall

Question 8 A micrometer is used to measure the diameters of two cylinders diameter of first cylinder = 12.78 ± 0.02 mm diameter of second cylinder = 16.24 ± 0.03 mm The difference in the diameters is calculated. What is the uncertainty in this difference?

• A ± 0.01 mm
• B ± 0.02 mm
• C ± 0.03 mm
• D ± 0.05 mm

Question 9 What is the reading shown on this milliammeter?

• A 2.35 mA
• B 2.7 mA
• C 3.4 mA
• D 3.7 mA

Question 10 A student carries out a series of determinations of the acceleration of free fall g. The table shows the results. g / m s⁻² 4.91 4.89 4.88 4.90 4.93 4.92 What can be said about this experiment?

• A it is accurate and precise
• B it is accurate but not precise
• C it is not accurate and not precise
• D it is not accurate but is precise