Unit 1

Physical Quantities, Unitsand Measurement

Multiple-choice Qrestions

l. The diagram below shows the scale of a verniercalipers when its jaws are closed. What is the zero

reading?

0

cm

4. Compared to 10 kg of feathers, 8 kg of iron has

2. In a micrometer screw gauge, the ratchet is used

toA turn the circular scale

B correct the zero erroC lock the spindleD apply the correct pressure

3. Alump of metal of mass 40 g and density 8 g/cm3

is lowered into a displacement can as shown inthe diagram.

5. Which of the following is a scalar quantity?A The braking force needed to stop a car

B The effort needed to hammer a nail into wood

C The thermal energy needed to boil some

waterD The thrust needed to lift a rocket off the

ground ( )

6. A student has been asked to calculate the volumeof a piece of wire, which is about 80 cm longand about 0.2 cm in diameter. Which measuring

instruments should the student use?

Length DiameterA metre rule vernier caliperB metre rule micrometer screw gauge

C micrometer vernier caliper screwgauge

D vernier caliper micrometer screw gauge()

7. A micrometer screw gauge shows a zero error as

represented by the diagram. When it is used to take

a reading, it must be corrected by

A less mass and less inertiaB less mass and more inertiaC more mass and less inertiaD more mass and more inerlia

A adding 0.02 mmB subtracting 0.02 mmC adding 0.002 mmD subtracting 0.002 mm

(

1

A +0.08 cmC -O.03 cm

B -O.07 cmD {).02 cm ()

()

()

()What is the volume of water displaced?A 5cm3 B 8cm3C 32 cm3 D 40 cm3

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8. Weights attached to two suspended strings aregiven small displacements and allowed to swingfreely. Their periods of oscillation will be equal ifthey have the sameA length of stringB mass

C initial displacementD amplitude of swing

9. The periodic time of a simple pendulum can besignificantly reduced byA increasing the mass of the pendulumB decreasing the mass of the pendulumC decreasing the length ofthe pendulumD increasing the length ofthe pendulum

14. A simple pendulum oscillates between P and R. Ifthe period of pendulum is 2.0 s, what is the timeit takes to move from Q to R?

P R

A 0.5sC 1.5s

()

A 5cm3C 32 cm3

B 8cm3D 40 cm3 ()

()

()

coo

() B 1.0 s

D 5.0s

10. Ten identical steel balls were immersed in a

measuring cylinder containing 20 cm3 of water.The reading of the water level rose to 50 cm3.

If the density of steel is 9.0 g cm-3, what is themass of one ball?A 39 B 27gC 45e D 21og ( )

I 1 . The density of a gold bar is 19.0 g cm-3. When ahole of volume 1.0 cm3 is drilled into the bar, thedensity of the gold bar will be

A 18.0 g cmr B 19.0 g cm-3

C 19.5 g cmr D 20.0 g cmr ( )

12. Which one of the following statements regardingthe period of a simple pendulum is correct?A It is independent of mass.

B It doubles when length doubles.C It does not change when the pendulum is

brought up to a very high mountain.D It decreases when the length increases.

()

13. A lump of metal of mass 40 g and density8.0 g cm 3 is lowered into a displacement can as

shown in the diagram below. What is the volumeof water displaced?

water

15. A pendulum makes 50 complete oscillations in 20seconds. What is the frequency of the oscillations?A O.4Hz B 2.5H2C 20Hz D l000Hz ( )

16. The diameter of a steel ball is measured using a

micrometer screw gauge. A student takes an initialzero reading and then a reading of the diameter.The following diagrams show enlargements of thescrew gauge readings.

zero reading

diameter reading

What is the diameter of the ball?A 3.48 mm B 2.04 mmC 1.98mm D l.9lmm

11 . The bob of a simple pendulum is swingingbetween X and Y.

It takes 9.4 s to swing from X to Y and back to X20 times.

0mm

metal

displaced

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18. The periodic time of oscillation of a simplependulum may be significantly reduced by

A decreasing the mass of the pendulum bobB decreasing the angle of the swing of the

pendulumC decreasing the length ofthe pendulumD increasing the mass of the pendulum bob

(

19. A student used a micrometer screw gauge to

measure the thickness of a metal sheet. The

diagram shows part of the micrometer.

X a)"

What is the period of the pendulum?A 0.47 s B 0.94 s

C 47s D 94s

What is the thickness of the metal sheet?

A 5.31 mm B 5.531 mmC 7.531mm D 7.81mm

21. The results obtained in an experiment to determinethe density of a plastic material are illustrated inthe diagram below.

plasticmaterial 85 cm3

103 cm3

plasticmaterial

What is the density of the plastic material?

A 400 x l0-2 g cm-3 B 25 x l0-2 g cm 3

C 5.3 x 10-2 g cm-3 D 4.4 x l0-2 g cmr(

22. An astronaut lands on a planet where the

acceleration of free fall at its surface is greater

than that on Earth. Which one of the followingwill be the same as on Earth?

A The period of oscillation of a simple pendulum

B The weight of the astronaut as measured bya spring balance

C The ease of changing the motion of aswinging can of sand

D The height reached by the astronaut when hejumps with the same initial velocity ( )

23. The diameter and length of a wooden rod of mass

22 gare 1 cm and 40 cm respectively.What is the density of the wooden rod in glcm3?

A 0.35 B 0.55c 0.70 D r.43 ( )

24. What would you use to measure the diameter of a

beaker in a lab?A micrometer screw gaugeB measuring tape

C venier calipersD metre rule ( )

o

()

()

20. An astronaut has a mass of 60 kg on Earth. He canjump 1.5 m high on the surface of Earth. Which ofthe following statements regarding the distance he

can on jump on the Moon and the correspondingreason are correct? Assume that the accelerationdue to gravity on the Moon is 1.6 m s-2.

Distance he canjump on the Moon Reason

A higher than his mass is less1.5 m than on Earth

B higher than his weight is less1.5 m than on Earth

C lower than his weight is more1.5 m than on Earth

D lower than his weight is more1.5 m than on Earth

()

04.5 g

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25. We say that the density of iron is 7.9 g cmJ. Thiscan also be written as

30. The diagram shows the banel (S) and the rotatingthimble (T) of a micrometer screw gauge.

T

The divisions shown above the horizontal line onthe barrel are millimetres and those below the lineon the barrel are the half-millimetres. There are 50divisions around the rim of the thimble of whichsome are shown in the diagram.The correct reading of the instrument, as shown,IS

A 7.9 kg mJC 790 kg mr

A 0.274H2C 1.83 Hz

A 5.224cmC 7.24mm

B 79kgmrD 7900 kg mr

()

()

()

S

26. It takes 36.5 s for a pendulum to swing from X toY and back again 20 times. What is the frequencyof the pendulum?

oA 2.20mmC 2.25 mm

B 2.23 mmD 2.28mm

27. An object X floats in liquid R but sinks in liquidS. Which of the following statements is correct?A Liquid R is less dense than object X.B Liquid S is denser than object X.C Liquid S is less dense than liquid R.D Liquid S is denser than liquid R. ( )

28. In the diagram below, the horizontal scale givesthe reading in mm above the axis and half mmbelow the axis. What is the micrometer readingshown?

31. Five identical iron balls, each of mass 25 g, wereimmersed in a measuring cylinder containing30 cm3 of water. The reading of the water levelrose to 50 cm3. What was the density of the iron?A 0.50 g cmi B 1.25 g cmiC 5.00 g cmr D 6.25 gcm3 ( )

32. Apendulum clock is foundto gain 10 minutes perday. This clock can be corrected by

-.

A increasing the amplitude of oscillationB decreasing the amplitude of oscillationC increasing the length ofpendulumD decreasing the length ofpendulum

()

33. The diagram below shows some liquid in a

measuring cylinder. What is the volume of theliquid?

cm3

50-

40-

B 0.548 HzD 2.74H2

B 5.274mmD 1.74mm

30

25

20

15

()

()

29. A simple pendulum is 1.0 m long and carries a

50 g bob. It takes 0.8 s to complete I swing. Ifthe 50 g bob is replaced by a 200 g bob (with the

length unchanged), how long does it take for the

new pendulum to comPlete I swing?

A 0.4s B 0.8sC 1.6s D 3.2s ( )

l_l"-2

B 43 cm3

D 45 cm3A 42cm3C Mcms

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34. A piece of wire is wound tightly round a pen as

shown in the diagram. The turns are next to one

another but not overlapping.

of wire

When there are 700 turns of the wire, the lengthof pen covered by the wire is found to be 4.9 cm.What is the average diameter of the wire?A 0.07 mm B 0.35 mmC 0.49 mm D 0.70 mm ( )

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Short- structured Qrestions

1. (a) State what is meant by 'the density of a substance' tll

(b) A cube of sides 2.0 cm each has a density of 6.0 g cm-3. A hole of volume 1.0 cm-3 is drilledinto the cube. The hole is then filled up with a certain material of density 5.0 g cm 3. Calculatethe density of the composite cube. t3l

2. (a) Define density tll

(b) 360 g of a liquid A of density 1.20 g cm-3 were mixed with 100 g of liquid B of density1.00 g cm-3. Showing your working, calculate (i) the volume, and (ii) the density, of themixture. Assume that no reaction occurs on mixing. t4l

3. A tin containing 5000 cm3 of paint has a mass of 7.0 kg.(a) If the mass of the empty tin, including the lid, is 0.5 kg, calculate the density of the paint. [2]

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(b) If the tin is made of a metal which has a density of 7800 kg m-t, calculate the volume of metalused to make the tin and the lid. l2l

Long-structured Qrestion

1. (a) Define the period of a simple pendulum.

(b) Describe briefly how you would determine the period of an oscillation of the pendulum.

(c) A pupil obtains the following values for 20 oscillations of a pendulum.

12.6 s,12.7 s,12.5 s, 12.6 s,12.7 s

Determine the period of the pendulum.

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