0%

DP IB Physics: SL

Topic Questions

Home / IB / Physics: SL / DP / Topic Questions / 1. Measurement & Uncertainties / 1.2 Uncertainties & Errors / Multiple Choice


1.2 Uncertainties & Errors

Question 1

Marks: 1

Systematic and random errors can be compared.

What are the properties that apply to random errors?

1  The error is consistently too high or too low and by different amounts

2  The error is constantly too high or low and by the same amount each time

3  The error can be fully eliminated

4  The error cannot be fully eliminated

5  The error can be reduced by averaging repeated measurements

6  The error cannot be reduced by averaging repeated measurements

  • 1, 3 and 6

  • 2, 4 and 6

  • 2, 3 and 6

  • 1, 4 and 5

Choose your answer
  

Question 2

Marks: 1

The measurement of a physical quantity may be subject to random errors and systematic errors.

Which statement is correct?

  • random errors can be reduced by taking the average of several measurements

  • random errors are always caused by the person taking the measurement

  • a systematic error cannot be reduced by adjusting the apparatus

  • a systematic error results in a different reading each time the measurement is taken

Choose your answer
  

Question 3

Marks: 1

A stone falls from rest to the bottom of a water well of depth d. The time t taken to fall is 3.0 ± 0.3 s. The depth of the well is calculated to be 30 m using d = begin mathsize 14px style 1 half end styleat2. The uncertainty in a is negligible.

What is the absolute uncertainty in d?

  • ± 0.6 m

  • ± 3 m

  • ± 24 m

  • ± 6 m

Choose your answer
  

Question 4

Marks: 1

The diagram shows an experiment to measure the speed of a small ball falling at constant speed through a clear liquid in a glass tube.q14_uncertainties--errors_ib-sl-physics-mcq

There are two marks on the tube. The top mark is positioned at 15 ± 1 mm on the adjacent rule and the lower mark at 285 ± 1 mm. The ball passes the top mark at 2.50 ± 0.02 s and passes the lower mark at 4.50 ± 0.02 s.

The constant speed of the ball is calculated to be 135 mm s–1.

Which expression calculates the fractional uncertainty in the value of this speed?

  • begin mathsize 16px style 2 over 270 plus fraction numerator 0.04 over denominator 2.00 end fraction end style

  • begin mathsize 16px style 1 over 270 plus fraction numerator 0.02 over denominator 2.00 end fraction end style

  • begin mathsize 16px style 1 over 15 plus fraction numerator 0.02 over denominator 2.50 end fraction end style

  • begin mathsize 16px style 1 over 285 plus fraction numerator 0.02 over denominator 4.50 end fraction end style

Choose your answer
  
Key Concepts
Uncertainties

Question 5

Marks: 1

The strain energy W of a spring is determined from its spring constant k and extension x. The spring obeys Hooke’s law and the value of W is calculated using the equation shown.

                                                                 W = begin mathsize 16px style 1 half end stylekx2

The spring constant k is 200 ± 1 N m–1 and the extension x is 0.040 ± 0.004 m.

What is the percentage uncertainty in the calculated value of W?

  • 20%

  • 20.5%

  • 10%

  • 10.5%

Choose your answer
  
Key Concepts
Uncertainties

Question 6

Marks: 1

In an experiment investigating the electrolysis of copper, a student sets out to find the electrochemical equivalent, Z.

The electrochemical equivalent of a substance is the amount of substance deposited on a cathode per Coulomb of charge.

This can be determined using the equation:

                                             Zbegin mathsize 16px style fraction numerator m subscript 1 minus m subscript 2 over denominator I t end fraction end style

Where:

  • Mass of cathode before passing current, m subscript 1= (54.39 ± 0.01) × 10–3 kg
  • Mass of cathode after passing current, m subscript 2= (52.06 ± 0.01) × 10–3 kg
  • Current, begin mathsize 16px style I end style= 3.00 ± 1 A
  • Time, t = 4800 ± 100 s

What is the largest possible value of Z from these readings?

  • begin mathsize 16px style 233 over 940 end style × 10–6 kg C–1

  • begin mathsize 16px style 231 over 940 end style × 10–6 kg C–1

  • begin mathsize 16px style 235 over 940 end style × 10–6 kg C–1

  • begin mathsize 16px style 253 over 720 end style × 10–6 kg C–1

Choose your answer
  

Question 7

Marks: 1

The sides of a square are measured to be 8.0 ± 0.2 cm.

Which of the following gives the area of the square and its uncertainty?

  • 64.0 ± 0.2 cm2 

  • 64.0 ± 0.4 cm2 

  • 64.0 ± 3.2 cm2 

  • 64.0 ± 1.6 cm2 

Choose your answer
  

Question 8

Marks: 1

In an experiment, a radio-controlled car takes 1.50 ± 0.05 s to travel 30.0 ± 0.1 m.

What is the car’s average speed and the uncertainty in this value?

  • 20.0 ± 0.732 m s–1

  • 20.0 ± 0.0366 m s–1

  • 20.0 ± 0.066 m s–1

  • 20.0 ± 9.91 m s–1

Choose your answer
  

Question 9

Marks: 1

The diagram shows a thermometer reading of a liquid's temperature, before and after heating. 

sl-mcq-1-2-hard-q10

What is the best estimate for the temperature increase of the liquid?

  • (54.0 ± 0.5) degrees

  • (54 ± 1.0) degrees

  • (54 ± 1) degrees

  • (54.0 ± 2.0) degrees

Choose your answer
  

Question 10

Marks: 1

A student collects values of the time period, T, of a pendulum at different lengths of string, L. They want to investigate the relationship:

                                                                T = 2π begin mathsize 16px style square root of L over g end root end style

They plot the values on a graph along with the error bars associated with each point, as shown in the diagram.

q20_uncertainties--errors_ib-sl-physics-mcq 

What is the percentage uncertainty in the experimental value of g?

  • begin mathsize 16px style 43 over 32 end style%

  • begin mathsize 16px style 43 over 1600 end style%

  • begin mathsize 16px style 43 over 800 end style%

  • begin mathsize 16px style 215 over 8000 end style%

Choose your answer