# Practice MCQs For Mass, Weight and Density, Work, Energy and Power

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This quiz contains practice questions for GCE ‘O’ level topics: Mass, Weight and Density, Work, Energy and Power. There are explanations for some of the questions after you submit the quiz. If you could not figure out why a particular option is the answer, feel free to drop a comment below or ask a question in ‘O’ & ‘A’ Level Discussion section of the forum. If you wish to contribute questions to this quiz, please contact us.

The quiz comprises of 10 questions, which are randomly selected from a large pool of questions. After completion, you can refresh the page and try the quiz again for a new set of 10 questions.

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1. Which energy changes take place when a pedalling cyclist uses a generator (dynamo) to light his bicycle lamp?
2. Which of the following about energy is false?
3. A box X full of large granite rocks is weighed. An identical box Y full of small granite chippings is then weighed.

Which box weighs more and why?
4. A girl of weight 500 N runs up a flight of stairs in 10 seconds. The vertical height of the stairs is 5 m.

What is the average power developed by the girl?
5. Which statement is correct about the position of the centre of gravity of a uniform solid?

The centre of gravity of a uniform solid
6. Ten identical steel balls, each of mass 27 g, are immersed in a measuring cylinder containing 20 $cm^{3}$ of water.

The reading of the water level rises to 50 $cm^{3}$.

What is the density of the steel?
7. Four students exercise in a gym.

Which student does the most work?
Exercise Time (s)Power Developed (W)
A50250
B100150
C200200
D25030
8. A box slides down a rough incline plane. Which of the following describes how energy is being conserved?
9. What can be used as the unit of energy?
10. Inertia is the resistance of a object to any change in its state of motion, including a change in direction. Which property is a measure of the body's inertia?

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### 21 thoughts on “Practice MCQs For Mass, Weight and Density, Work, Energy and Power”

1. This website is very helpful…..Is there chemistry and biology website like this…plz tell me….

2. Consider a stationary box at height x. The block is lifted by a student such that it comes to a rest at higher height y.

Consider the following discussion between two students:

Student 1: I exert an upward force on the box, which moves upward, so I do positive work on the box. The Earth exerts a downward force, so it does negative work on the box. The box begins and ends at rest, so its kinetic energy hasn’t changed. That means that the net work on the box is zero, so the work on the box by my hand and the work on the box by the Earth must have the same absolute value.

Student 2: But the box has moved upward, so its potential energy has increased. That means that the net work on the block must be positive, so the work on the box by your hand must be greater than the work on the box by the Earth.

What can you say about the reasoning given by the two students?
1. They are both incorrect.
2. Student 2 is correct and student 1 is incorrect.
3. They are both correct.
4. Student 1 is correct and student 2 is incorrect.

• student 2 is incorrect as they say that the work done on the box by the hand must be greater than the work done on the box by gravity, which, if it was true, would mean that the box is accelerating. Student 1 however says that the work done on the box must be zero, and have the same value.

idk just guessing

3. volume of ten steel balls =50-20=30
volume of a steel ball=30/10=3 cm^3
mass of a steel ball=27 g
density=mass/volume=27g/3cm^3=9g/cm^3

• Thank you very much
I was also thinking about it when he incorrected it

4. I also have a question.
Which of these have a greater refractive index and why?
A) water
B)ice

1)water, since it has more density
2) ice, since it has more density
3) water, since it has less density
4) ice, since it has less density

• water since it has more density

• so what should i do

5. 1. Ten identical steel balls, each of mass 27 g, are immersed in a measuring cylinder containing 20 cm3cm3 of water.
The reading of the water level rises to 50 cm3 .

What is the density of the steel?

a)8.1 g/cm3
b)13.5 g/cm3
c)9.0 g/cm3[correct]
d)0.90 g/cm3
The volume of the ten steel balls is 50 – 20 = 30 . Density is calculated using Density= mass/volume.

Can someone explain to me why c is correct?
But I think d is correct.

• Each of the steel balls is 27 g.

The total mass will be 27 x 10 = 270 g.

• Dont we use 270g for calculating the density

Coz
Mass of steel ball =27g
Volume of steel ball = 50cm^3- 20cm^3 =30cm^3
Density of steel ball = mass /volume
rho = 27g/30cm^3=0.9gcm^-3.
(By Archimedes’ principle,
volume of body = volume of the liquid displaced by the body.)

• Density=mass/volume
Volume of 10 metal balls =volume of the water that rose
=50-20
=30cm^3
Mass of 10 steel balls=mass of 1 steel ball ×10
=27×10
=270gm
Density=mass/volume
=270/30
=9gm/cm^3

6. good way to test your ability

7. oh wait I get it!! Sorry! 😛 My bad!