Physics SL
Questionbank
Measurements and Uncertainties
Question difficulty level:
Basic
Moderate
Challenging
Difficult
Black Hole
Basic
Moderate
Challenging
Difficult
Black Hole
A bit more about difficulty levels (click)
Basic: Simple, usually onestep or definitionstyle questions to help you revise the basics.
Moderate: At the level of easier IB exam questions. Slightly more challenging than oneplane problems.
Challenging: Typical, mediumlevel examstyle questions to help you solidify your knowledge.
Difficult: This is how more challenging IB exam questions look like. If you can solve these with ease, you are in a good shape :)
Black Hole: Extra challenge for those with lightspeed thinking! Very few questions on your exam will be this difficult.
Tips on how to get the most out of the Questionbank
Paper 1
Question 1
The number of significant figures in 0.02670 is:
 3
 4
 5
 6
Answer
B.
Video Solution
Done Under 90
Question 2
Which of the following are two vector quantities?
 Speed, Mass
 Speed, Force
 Velocity, Mass
 Force, Velocity
Answer
D.
Video Solution
Done Under 90
Question 3
Repeating readings in an experiment reduces:
 Both random and systematic errors
 Random errors only
 Systematic errors only
 Neither random, nor systematic errors
Answer
B.
Video Solution
Done Under 90
Question 4
Which of the following are two fundamental SI units?
 mole, kelvin
 ampere, pascal
 joule, meter
 second, newton
Answer
A.
Video Solution
Done Under 90
Question 5
A ball of 0.18 kg is traveling at a speed of 3.210 m s^{1}. The mass and the velocity of the ball are used to calculate the magnitude of its momentum. What is the correct number of significant figures for the magnitude of the ball’s momentum?
 2
 3
 4
 5
Answer
A.
Video Solution
Done Under 90
Question 6
What is the unit of pressure in fundamental SI units?
 N m^{1}
 N m^{2}
 kg m^{1} s^{2}
 kg m^{2} s^{2}
Answer
C.
Video Solution
Done Under 90
Question 7
A particle is moving upwards in a straight line at constant speed. Which diagram represents the forces acting on this particle?
Answer
D.
Video Solution
Done Under 90
Question 8
Which of the following quantities has the fundamental SI unit combination of kg m s^{1}?
 Power
 Energy
 Impulse
 Force
Answer
C.
Video Solution
Done Under 90
Question 9
The side length of a square is measured to be y \pm \Delta y. What is the fractional uncertainty in the area of the square?
 \frac{\Delta y}{y}
 \frac{2 \Delta y}{y}
 \frac{\Delta y}{2y}
 \left ( \frac{\Delta y}{y} \right )^{2}
Answer
B.
Video Solution
Done Under 90
Question 10
What is the order of magnitude, in cm, of an adult human being who has an average height?
 1
 0
 1
 2
Answer
D.
Video Solution
Done Under 90
Question 11
The mass of a car is 1000 kg\pm5% It is moving at a constant speed of 30.0 m s^{1}\pm3%. What is the percentage uncertainty in the kinetic energy of the car?
 8 %
 11 %
 14 %
 45 %
Answer
B.
Video Solution
Done Under 90
Question 12
Which of the following is a unit of acceleration?
 J kg^{1} m^{1}
 N kg^{1} m^{1}
 J kg m^{1}
 N kg m^{1}
Answer
A.
Video Solution
Done Under 90
Question 13
What is the size of a carbon nucleus?
 0.0027 fm
 0.0027 pm
 0.0027 nm
 0.0027 \mum
Answer
B.
Video Solution
Done Under 90
Question 15
The mass of an object is 5.0 \pm 0.1 kg and its speed is 20 \pm 1 m s^{1}.
What is the percentage uncertainty in the kinetic energy of the object?
 6%
 7%
 12%
 25%
Answer
C.
Video Solution
Done Under 90
Question 16
Two masses, X and Y, are 62\pm2 kg and 28\pm1 kg respectively. Which of the following has the largest fractional uncertainty?
 2X + Y
 X – 2Y
 \frac{3Y}{X}
 4XY
Answer
B.
Video Solution
Done Under 90
Question 17
A coalfired power plant uses 9 \times 10^{6} kg of coal per day. All the coal that is used in the power plant is composed of carbon12 atoms.
What is the best estimate for the number of carbon12 atoms used per month in the power plant?
 10^{9}
 10^{24}
 10^{31}
 10^{34}
Answer
D.
Video Solution
Done Under 90
Question 18
A student carries out an experiment to examine how the kinetic energy of an object varies with the speed of the object. The results are shown on the graph.
What can be deduced about the type of errors in the student’s measurements?
Random errors 
Systematic errors 

A.  Small  Small 
B.  Small  Large 
C.  Large  Small 
D.  Large  Large 
Answer
B.
Video Solution
Done Under 90
Question 19
A stone is thrown with initial velocity v at an angle \theta to the horizontal. The magnitude of the vertical component of the stone’s velocity is 10 m s^{1}.
What is the value of \theta?
 sin^{1}\left ( \frac{10}{v} \right )
 sin^{1}\left ( \frac{v}{10} \right )
 cos^{1}\left ( \frac{10}{v} \right )
 cos^{1}\left ( \frac{v}{10} \right )
Answer
A.
Video Solution
Done Under 90
Question 20
A box is in the shape of a rectangular prism. The length, width and height of the box are measured to be 5 cm, 10 cm, and 20 cm respectively. The uncertainty in each measurement is \pm 1 cm.
What is the absolute uncertainty in the volume of the box?
 3.5 cm^{3}
 100 cm^{3}
 350 cm^{3}
 500 cm^{3}
Answer
C.
Video Solution
Done Under 90
Question 21
The volume of a cone is 30\pi \pm 0.9 \pi cm^{3} and its height is 100 \pm 7 mm. The volume of a cone can be calculated using V = \frac{1}{3} \pi r^{2} h where V is volume, r is radius and h is height.
What is the absolute uncertainty in the diameter of the cone?
 0.01 m
 0.005 m
 0.003 m
 0.002 m
Answer
C.
Video Solution
Done Under 90
Question 22
Three forces, \overrightarrow{A}, \overrightarrow{B} and \overrightarrow{C}, act on object X as shown on the diagram. Object X moves at constant velocity.
Consider the following three equations:
I. \overrightarrow{A} + \overrightarrow{B} =  \overrightarrow{C}
II. \left  \overrightarrow{B} \right cos(\alpha) = \left  \overrightarrow{C} \right cos\left ( \frac{\pi}{2}  \alpha \right )
III. \left  \overrightarrow{A} \right  = \left  \overrightarrow{B} \right sin(\alpha) + \left  \overrightarrow{C} \right cos(\alpha)
Which of these three equations are correct?
 I and II only
 I and III only
 II and III only
 I, II and III
Answer
D.
Video Solution
Done Under 90
Question 23
A stone is attached to a metal rod and rotated in a horizontal circle. The centripetal acceleration, a, of the stone is measured for different rotational time periods, T.
Given that random errors were minimised during the experiment, which of the following graphs will have a straight line of best fit?
 a against T^{2}
 a^{2} against T
 a against T^{2}
 a^{2} against T
Answer
C.
Video Solution
Done Under 90
Question 24
Two quantities, x and y, are related as shown on the graph. The vertical axis intercept of the graph is c and the gradient of the graph is \frac{1}{m}.
Which of the following equations correctly shows the relationship betweenx and y?
 c = y  mx
 c = my  x
 x = my  c
 x = my  mc
Answer
D.
Video Solution
Done Under 90
Question 25
In an experiment, the following values are measured and given together with their uncertainties:
a = 2.0 \pm x
b = 16 \pm 2%
c = 0.50 \pm 0.07
Then, H is calculated using the formula H = \frac{3a^{3}}{2 \sqrt{b} \times c}. For the values given above, the absolute uncertainty in H is \pm 1.8.
What is the value of x?
 0.1
 0.2
 0.3
 0.4
Answer
A.