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Units and Measurements — Homi Bhabha Class 6 Physics MCQs with Solutions
Free Homi Bhabha Class 6 Physics Units and Measurements MCQs with step-by-step solutions covering Standard & Non-standard Units, Measuring Length, Mass & Time, Measuring Temperature, Unit Conversions & Estimation. Practise online on Prepizo — no login needed.
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Sample questions with solutions
Q1 — Standard & Non-standard Units · easy · theory
Which of the following is a standard unit of length?
A. Footstep
B. Handspan
C. Cubit
D. Metre ✓ Correct
Solution: The metre is a standard (SI) unit whose length is fixed and the same everywhere. Handspan, footstep and cubit change from person to person.
Q2 — Standard & Non-standard Units · easy · theory
Which of these is a non-standard unit for measuring length?
A. Handspan ✓ Correct
B. Kilometre
C. Centimetre
D. Metre
Solution: A handspan (the distance across an open hand) differs for each person, so it is a non-standard unit. Metre, centimetre and kilometre are fixed standard units.
Q3 — Standard & Non-standard Units · easy · theory
Why do we use standard units instead of body parts like the cubit?
A. Standard units give the same value for everyone ✓ Correct
B. Body parts are too long
C. Body parts cost money
D. Standard units are older
Solution: A standard unit has one fixed size, so measuring the same thing gives the same answer for everyone. Body parts vary from person to person.
Q4 — Standard & Non-standard Units · easy · theory
The system of units used by scientists all over the world is called the:
A. SI system ✓ Correct
B. Market system
C. Foot system
D. Body system
Solution: SI stands for the International System of Units (metre, kilogram, second, and so on), which scientists everywhere agree to use.
Q5 — Measuring Length, Mass & Time · easy · theory
Which instrument is used to find the mass of vegetables in a shop?
A. Weighing balance ✓ Correct
B. Ruler
C. Thermometer
D. Clock
Solution: A weighing balance (or scale) measures mass. A ruler measures length, a clock measures time, and a thermometer measures temperature.
Q6 — Measuring Length, Mass & Time · easy · theory
Which instrument would you use to measure the length of your notebook?
A. Stopwatch
B. Thermometer
C. Ruler (scale) ✓ Correct
D. Weighing balance
Solution: A ruler or scale is marked in centimetres and millimetres, so it is used to measure length such as the size of a notebook.
Q7 — Measuring Length, Mass & Time · easy · theory
The SI (standard) unit of time is the:
A. minute
B. second ✓ Correct
C. day
D. hour
Solution: Time is measured in seconds in the SI system. Hours, minutes and days are larger units built from seconds.
Q8 — Measuring Length, Mass & Time · easy · theory
Which device is best for measuring how long a runner takes to finish a race?
A. Measuring jar
B. Ruler
C. Balance
D. Stopwatch ✓ Correct
Solution: A stopwatch measures short time intervals accurately, so it is used to time a race.
Q9 — Measuring Temperature · easy · theory
Which instrument is used to measure temperature?
A. Weighing balance
B. Thermometer ✓ Correct
C. Stopwatch
D. Ruler
Solution: A thermometer measures how hot or cold something is, that is, its temperature.
Q10 — Measuring Temperature · easy · theory
Which unit is commonly used to measure everyday temperature?
A. metre
B. second
C. degree Celsius (°C) ✓ Correct
D. kilogram
Solution: Everyday temperature is usually given in degrees Celsius (°C). Metre, kilogram and second measure length, mass and time.
Q11 — Measuring Temperature · easy · theory
The silvery liquid traditionally used inside a clinical thermometer is:
A. mercury ✓ Correct
B. water
C. milk
D. oil
Solution: A clinical thermometer traditionally uses mercury, a liquid metal that expands and rises evenly as the temperature increases.
Q12 — Measuring Temperature · easy · theory
The normal temperature of a healthy human body is about:
A. 100 °C
B. 37 °C ✓ Correct
C. 0 °C
D. 50 °C
Solution: A healthy person’s body temperature is about 37 °C. A much higher reading usually means the person has a fever.
Q13 — Unit Conversions & Estimation · easy · numerical
How many centimetres are there in 1 metre?
A. 100 ✓ Correct
B. 1000
C. 10
D. 1
Solution: 1 metre is equal to 100 centimetres.
Q14 — Unit Conversions & Estimation · easy · numerical
How many grams are there in 1 kilogram?
A. 10
B. 1000 ✓ Correct
C. 500
D. 100
Solution: 1 kilogram is equal to 1000 grams.
Q15 — Unit Conversions & Estimation · easy · numerical
How many minutes are there in 1 hour?
A. 100
B. 24
C. 30
D. 60 ✓ Correct
Solution: 1 hour is equal to 60 minutes.
Q16 — Unit Conversions & Estimation · easy · numerical
How many metres are there in 1 kilometre?
A. 10
B. 1000 ✓ Correct
C. 100
D. 60
Solution: 1 kilometre is equal to 1000 metres.
Q17 — Standard & Non-standard Units · hard · theory
Two friends measure the same room using their own "footsteps". Ravi gets 20 footsteps and Sara gets 24. Why is their answer different?
A. Their footsteps are different lengths ✓ Correct
B. They both counted wrongly
C. The room changed its size
D. Footstep is a standard unit
Solution: The room is the same size. Because a footstep is non-standard, Sara’s shorter footsteps mean she needs more of them to cover the same distance.
Q18 — Standard & Non-standard Units · hard · theory
Which statement about standard units is correct?
A. They can be used only in India
B. They give different results for different people
C. They change with the weather
D. They are fixed and the same for everyone ✓ Correct
Solution: A standard unit has one fixed, agreed size, so it gives the same measurement for everyone, everywhere, at all times.
Q19 — Measuring Length, Mass & Time · hard · numerical
A pencil is placed along a ruler. One end is at the 2 cm mark and the other end is at the 15 cm mark. How long is the pencil?
A. 2 cm
B. 13 cm ✓ Correct
C. 15 cm
D. 17 cm
Solution: The length is the difference between the two marks: 15 cm − 2 cm = 13 cm.
Q20 — Measuring Length, Mass & Time · hard · theory
Why should the marked edge of a ruler be placed right against the object being measured?
A. To make the object heavier
B. To avoid a gap that would give a wrong reading ✓ Correct
C. To measure time as well
D. To change the units
Solution: If there is a gap between the ruler marks and the object, the reading is inaccurate. Keeping the marked edge touching the object gives the correct length.
Q21 — Measuring Temperature · hard · numerical
In the morning the temperature was 18 °C, and by noon it rose to 33 °C. By how many degrees did the temperature rise?
A. 15 °C ✓ Correct
B. 18 °C
C. 33 °C
D. 51 °C
Solution: The rise is the difference: 33 °C − 18 °C = 15 °C.
Q22 — Measuring Temperature · hard · theory
Besides the degree Celsius, another unit of temperature used in some countries is the degree:
A. Fahrenheit ✓ Correct
B. metre
C. Newton
D. litre
Solution: The degree Fahrenheit (°F) is another temperature unit, used in countries like the USA. Metre, litre and newton measure length, volume and force.
Q23 — Unit Conversions & Estimation · hard · numerical
A bottle holds 2 litres of water. How many millilitres is that? (1 litre = 1000 mL)
A. 20 mL
B. 2000 mL ✓ Correct
C. 20000 mL
D. 200 mL
Solution: Since 1 litre = 1000 mL, 2 litres = 2 × 1000 = 2000 mL.
Q24 — Unit Conversions & Estimation · hard · theory
Which of these is the best estimate for the length of a new pencil?
A. about 15 cm ✓ Correct
B. about 15 mm
C. about 15 m
D. about 15 km
Solution: A pencil is about 15 cm long. 15 m is room-sized, 15 km is a long journey, and 15 mm is only about the width of a fingernail.
Q25 — Standard & Non-standard Units · medium · theory
Long ago people measured cloth using the "cubit" (elbow to fingertip). Why was this a problem?
A. A cubit can measure only metal
B. A cubit is too small to measure cloth
C. A cubit needs a machine
D. Everyone's arm length is different ✓ Correct
Solution: Because arm lengths differ, one person’s cubit is not equal to another’s, so the same cloth measured different amounts. That is why fixed units are needed.
Q26 — Standard & Non-standard Units · medium · theory
Which set contains only standard units?
A. metre, footstep, second
B. handspan, footstep, cubit
C. metre, kilogram, second ✓ Correct
D. pace, kilogram, cubit
Solution: Metre, kilogram and second are all fixed SI standard units. The other sets include body-based (non-standard) units like handspan, footstep, cubit and pace.
Q27 — Standard & Non-standard Units · medium · theory
A "footstep" is called a non-standard unit because:
A. it can measure only short distances
B. its length changes from person to person ✓ Correct
C. it is used only by scientists
D. it is very accurate
Solution: One person’s footstep is longer or shorter than another’s, so it does not give a fixed, reliable value. That makes it a non-standard unit.
Q28 — Standard & Non-standard Units · medium · theory
The SI (standard) unit of mass is the:
A. metre
B. litre
C. kilogram ✓ Correct
D. second
Solution: Mass is measured in kilograms in the SI system. The metre measures length, the second measures time, and the litre measures volume.
Q29 — Measuring Length, Mass & Time · medium · theory
What is the best simple way to measure the length of a curved line on a map?
A. Lay a thread along the curve, then measure the thread with a ruler ✓ Correct
B. Use a straight ruler
C. Use a stopwatch
D. Use a weighing balance
Solution: A straight ruler cannot follow a curve. A thread can bend along the curve; you then straighten the thread and measure it with a ruler.
Q30 — Measuring Length, Mass & Time · medium · theory
While measuring length with a ruler whose end is worn out, you should:
A. start from the 0 mark or another clear full mark ✓ Correct
B. use a stopwatch instead
C. just guess the length
D. still start from the worn end
Solution: A worn end gives a wrong starting point. Starting from a clear mark (like 0) and reading correctly avoids the error.