Physics 9th New
Chapters: 1
MCQS
1 . What is the least count of Vernier Callipers?
a) 0.01 mm b) 0.001 mm c) 0.1 mm d) 1 mm
2 . Which of these is an example of a non-physical quantity?
a) Volume b) Density c) Fear d) Temperature
3 . What is the least count of a measuring tape?
a) 0.1 mm b) 1 mm c) 1 cm d) 10 mm
4 . Which of the following measures are likely to represent the thickness of a sheet of this book?
a) $6\times10^{-25}m$ b) $1.2\times10^{-15}m$ c) $4\times10^{-2}m$ d) $1\times10^{-4}m$
5 . Which part of the Vernier Callipers is used to measure external dimensions?
a) Inside jaws (C and D) b) Outside jaws (A and B) c) Main scale d) Vernier scale
6 . A displacement can is used to measure:
a) Mass of a liquid b) Mass of a solid c) Volume of a liquid d) Volume of a solid
7 . Which of the following is a base quantity?
a) Speed b) Area c) Volume d) Temperature
8 . What is the symbol for the SI unit ‘candela’?
a) cd b) ca c) cn d) cl
9 . What is parallax error caused by?
a) Incorrect position of eye b) Incorrect instrument calibration c) Environmental temperature changes d) Material expansion
10 . If the zero of the Vernier scale is on the right side of the main scale’s zero, what type of zero error is present?
a) Positive zero error b) Negative zero error c) No zero error d) Parallax error
11 . What is the least count of a metre rule?
a) 0.1 mm b) 1 mm c) 0.01 mm d) 1 cm
12 . The instrument that is most suitable for measuring the thickness of a few sheets of cardboard is:
a) Metre rule b) Measuring tape c) Vernier Callipers d) Micrometer screw gauge
13 . Two rods with lengths 12.321 cm and 10.3 cm are placed side by side, the difference in their lengths is:
a) 2.02 cm b) 2.0 cm c) 2 cm d) 2.021 cm
14 . How many divisions are typically on the circular scale of a micrometer screw gauge?
a) 10 b) 50 c) 100 d) 1000
15 . The prefix ‘milli’ corresponds to which power of ten?
a) $10^{-2}$ b) $10^{-3}$ c) $10^{-6}$ d) $10^{3}$
16 . A light year is a unit of:
a) Light b) Time c) Distance d) Speed
17 . What is the purpose of the ‘tail’ or ‘depth gauge’ in Vernier Callipers?
a) To measure external dimensions b) To measure internal dimensions c) To measure depths of hollow objects d) To adjust the scales
18 . When is addition and subtraction of numbers in scientific notation possible?
a) Always possible b) If they have different exponents c) If they have the same exponents d) If they are positive numbers
19 . What is the approximate thickness of a book page in scientific notation (in meters)?
a) $1.0\times10^{0}m$ b) $1.0\times10^{-2}m$ c) $1.0\times10^{-4}m$ d) $1.0\times10^{-6}m$
20 . When using a measuring cylinder, one precaution to take is to:
a) Check for the zero error b) Look at the meniscus from below the level of the water surface c) Take several readings by looking from more than one direction d) Position the eye in line with the bottom of the meniscus
21 . Which scientist invented Vernier Callipers?
a) Isaac Newton b) Galileo Galilei c) Pierre Vernier d) Albert Einstein
22 . One femtometre is equal to:
a) $10^{-9}$ m b) $10^{-15}$ m c) $10^{9}$ m d) $10^{15}$ m
23 . How is the unit of charge (coulomb) expressed in terms of base units?
a) Ampere per second b) Ampere x second c) Second per ampere d) Ampere squared
24 . What is the power of ten for the prefix ‘kilo’?
a) $10^{2}$ b) $10^{6}$ c) $10^{-3}$ d) $10^{3}$
25 . What does an electronic timer measure time intervals as short as?
a) One-hundredth of a second b) One-thousandth of a second c) One-ten thousandths of a second d) One-millionth of a second
26 . How many base units are there in the International System of Units (SI)?
a) Five b) Six c) Seven d) Eight
27 . What is the SI unit for amount of substance?
a) Gram b) Kilogram c) Mole d) Liter
28 . What is the main scale division marking on a Vernier Callipers?
a) 0.1 mm b) 0.5 mm c) 1 mm d) 1 cm
29 . Which of the following is a derived unit?
a) Kilogram b) Second c) Newton d) Ampere
30 . Which instrument is used to measure very small lengths such as the diameter of a wire or thickness of a metal sheet?
a) Metre Rule b) Measuring Tape c) Vernier Callipers d) Micrometer Screw Gauge
31 . The average distance from the Sun to the Earth is 138,000,000 km. How is this written in scientific notation?
a) $1.38\times10^{8}$ km b) $1.38\times10^{7}$ km c) $1.38\times10^{9}$ km d) $1.38\times10^{10}$ km
32 . What is the least count of a screw gauge if its pitch is 0.5 mm and it has 50 divisions on the circular scale?
a) 0.5 mm b) 0.01 mm c) 0.005 mm d) 0.1 mm
33 . What is the primary purpose of scientific notation? a) To confuse readers b) To make numbers longer c) To represent very large or very small numbers concisely d) To replace prefixes
34 . In a Vernier Callipers, ten smallest divisions of the Vernier scale are equal to nine smallest divisions of the main scale. If the smallest division of the main scale is half a millimetre, the Vernier constant is equal to:
a) 0.5 mm b) 0.1 mm c) 0.05 mm d) 0.001 mm
35 . Which type of error occurs due to the incorrect position of the eye when taking measurements?
a) Parallax error b) Systematic error c) Random error d) Zero error
36 . What is the purpose of prefixes in SI units?
a) To make units simple to write b) To make units more complex c) To change the base unit d) To represent non-physical quantities
37 . When a measurement without a unit is given, it is considered:
a) Accurate b) Precise c) Meaningless d) Standard
38 . What is a ‘unit’ in measurement?
a) A number b) A process of comparison c) A widely accepted standard quantity d) An unknown quantity
39 . The kilogram is unique among base units because:
a) It is the largest unit b) It is the only unit with a prefix c) It is only used for mass d) It is a derived unit
40 . What does ‘least count’ refer to in an instrument?
a) The largest measurement it can take b) The total number of divisions on its scale c) The maximum error in measurement d) The smallest measurement it can take accurately
41 . How is 50,000 cm written in meters using scientific notation?
a) $5\times10^{2}$ m b) $5\times10^{3}$ m c) $5\times10^{4}$ m d) $5\times10^{1}$ m
42 . Volume of water consumed by you per day is estimated in:
a) Millilitres b) Litres c) Kilograms d) Cubic metres
43 . Which of the following is a rule for writing SI prefixes and units?
a) Compound prefixes are allowed b) Units are written with no space apart c) Prefixes are written after the SI unit d) Compound prefixes are not allowed
44 . Which of the following is NOT a physical quantity?
a) Length b) Mass c) Anger d) Time
45 . What is the range of a measuring tape?
a) Millimetres only b) Centimetres only c) 1 mm to several metres d) Metres only
46 . In scientific notation, the numerical part of the quantity is written as a number from _____ to _____.
a) 0 to 9 b) 1 to 10 c) 0 to 10 d) 1 to 9
47 . What is the pitch of a screw gauge with a main scale marking of 0.5 mm and a thimble making one complete turn? a) 0.01 mm b) 1 mm c) 50 divisions d) 0.5 mm
48 . Which of the following is a unit of pressure?
a) Newton b) Joule c) Pascal d) Watt
49 . What is the definition of a ‘physical quantity’?
a) A quantity that can be measured directly or indirectly using tools and instruments b) Something that cannot be measured c) A quantity that expresses human emotions d) A quantity that only has a numerical value
50 . The International System of Units (SI) was recommended by the international committee on weights and measures in which year?
a) 1951 b) 1961 c) 1971 d) 1981
51 . Which instrument is generally used to measure length in the laboratory?
a) Measuring Tape b) Metre Rule c) Screw Gauge d) Vernier Callipers
52 . Four students measure the diameter of a cylinder with Vernier Callipers. Which of the following readings is correct?
a) 3.4 cm b) 3.475 cm c) 3.47 cm d) 3.5 cm
53 . What is the SI unit for electric current?
a) Volt b) Ampere c) Ohm d) Watt
54 . What is the range of the Vernier scale on a Vernier Callipers?
a) 1 mm b) 9 mm c) 10 mm d) 50 mm
55 . The least count of a screw gauge can also be 1 mm divided by 100 divisions, resulting in:
a) 0.01 mm b) 0.001 mm c) 0.1 mm d) 1 mm
56 . How are symbols for SI units generally written if they are not named after a scientist?
a) In capital letters b) In lowercase c) With a prefix always d) With an abbreviation
57 . Which of the following is a base unit for time?
a) Hour b) Minute c) Second d) Day
58 . What happens to the decimal point when a number is converted to scientific notation and the exponent of 10 is positive?
a) Moved to the right b) Moved to the left c) Remains in place d) Disappears
59 . If the zero of the circular scale of a screw gauge is below the horizontal line, how is the zero error treated?
a) It is added to the observed measurement b) It is ignored c) It indicates no error d) It is subtracted from the observed measurement
60 . Which one is a non-physical quantity?
a) Distance b) Density c) Colour d) Temperature
61 . The field of observation and experimentation to understand about the world around us is known as:
a) Philosophy b) Science c) History d) Arts
62 . What is the SI unit for luminous intensity?
a) Lux b) Candela c) Lumen d) Joule
Short Questions
- What are derived quantities? Give examples.
- How do you find the least count of Vernier Callipers?
- Define physical quantities.
- The end of a meter scale is worn out. Where will you place a pencil to find the length?
- What does an electronic timer measure?
- What is the pitch of a screw gauge?
- What is the SI unit for force? How is it derived?
- Explain positive zero error in Vernier Callipers.
- How many base units are there in the International System of Units (SI)? Name them.
- Which SI unit will you use to express the height of your desk?
- What are the two main types of physical quantities?
- What are base quantities? Give examples.
- Write the name and symbols of all SI base units.
- How do you find the least count of a screw gauge?
- Why is a standard unit needed to measure a quantity correctly?
- Convert 5000 grams into kilograms using prefixes.
- What is the least count of a metre rule?
- Why is a prefix used? Name three sub-multiples and three multiple prefixes with their symbols.
- What is the difference between precision and accuracy?
- Which instrument can be used to measure: (i) Internal diameter of a testtube. (ii) Depth of a beaker.
- How do you read the volume of a liquid in a measuring cylinder?
- What are the rules for writing SI units and prefixes?
- What is measurement? Name its two parts.
- Can a non-physical quantity be measured? If yes, then how?
- What is the significance of significant figures in a measurement?
- Explain negative zero error in Vernier Callipers.
- Write the name of 3 base quantities and 3 derived quantities.
- What is science based on?
- Write 0.00000000018 m in scientific notation.
- What is a micrometer screw gauge used for?
- Give examples of non-physical quantities.
- For what purpose, a Vernier Callipers is used?
- The minimum main scale reading of a micrometer screw gauge is 1 mm and there are 100 divisions on the circular scale. When the thimble is rotated once, 1 mm is its measurement on the main scale. What is the least count of the instrument? The reading for the thickness of a steel rod as shown in the figure. What is the thickness of the rod?
- Why do we need a standard unit for measurements?
- What is meant by zero error?
- It is difficult to locate the meniscus in a wider vessel. Why?
- You are provided with a meter scale and a bundle of pencils; how can the diameter of a pencil be measured using the meter scale with the same precision as that of Vernier Callipers? Describe briefly.
- Why is it better to place the object close to the meter scale?
- What are Vernier Callipers used for?
- What are prefixes in SI units used for?
- What is scientific notation?
- Suggest some natural phenomena that could serve as a reasonably accurate time standard.
- What is a standard quantity or unit?
- Name two main parts of Vernier Callipers.
- What is the primary function of the ratchet in a screw gauge?
- What are measuring cylinders used for?
- What is parallax error and how can it be avoided?
- Why might a standard system of measurement be helpful to a tailor?
- What is meant by: (a) 5 pm (b) 15 ps (c) 5 fs
- How is least count found?
- What is the least count of an instrument?
Long Questions
1. (a) Explain how the volume of an irregular solid is measured.(b) Give three examples of derived units in SI. How are they derived from base units? Describe briefly.
2. (a) Calculate the following and state your answer in scientific notation: $\frac{(3\times10^{2}\text{ kg})\times(4.0\text{ km})}{(5\times10^{2}\text{ s}^{2})}$. (b) The diameter of a wire is measured using a screw gauge as $0.86\text{ mm}$. Convert it into meters.
3. (a) State the number of significant digits in each measurement:
- (a) $0.0045\text{ m}$
- (b) $2.047\text{ m}$
- (c) $3.40\text{ m}$
- (d) $3.420\times10^{4}\text{ m}$
(b) What is meant by base and derived quantities? Give the names and symbols of SI base units.
4. (a) A Vernier Callipers gives a main scale reading of $3.4\text{ cm}$ and a Vernier scale reading of $6$. Find the total reading if the least count is $0.01\text{ cm}$. (b) Discuss different time-measuring devices and their importance.
5. (a) Write using correct prefixes:
- (a) $5.0\times10^{4}\text{ cm}$
- (b) $580\times10^{2}\text{ g}$
- (c) $45\times10^{-4}\text{ s}$
(b) A pendulum takes $35.4\text{ seconds}$ to complete $20$ oscillations. Find the time period of one oscillation.
6. (a) Solve the following addition or subtraction. State your answers in scientific notation:
- (a) $4\times10^{-4}\text{ kg} + 3\times10^{-5}\text{ kg}$
- (b) $5.4\times10^{-6}\text{ m} – 3.2\times10^{-5}\text{ m}$
(b) Convert the following into scientific notation:
- (a) $0.00025\text{ m}$
- (b) $4500000\text{ kg}$
7. (a) Explain Micrometer Screw Gauge and its working principle. (b) Discuss scientific notation with suitable examples.
8. (a) Define base and derived quantities with at least four examples. (b) Solve the following multiplication or division. State your answers in scientific notation:
- (a) $(5\times10^{4}\text{ m})\times(3\times10^{-2}\text{ m})$
- (b) $\frac{6\times10^{8}\text{ kg}}{3\times10^{4}\text{ m}^{3}}$
9. (a) Differentiate between precision and accuracy of a measurement with examples. (b) Write in scientific notation:
- (a) $0.0035\text{ m}$
- (b) $206.4\times10^{2}\text{ m}$
10. (a) A cube has a side length of $4.2\text{ cm}$. Calculate its volume in $\text{cm}^{3}$ and $\text{m}^{3}$. (b) Calculate the number of seconds in a (a) day, (b) week, and (c) month, and state your answers using prefixes.
11. (a) Discuss different types of errors in measurement. (b) What are physical and non-physical quantities? Explain with examples.
12. (a) Explain Vernier Callipers with the method of taking measurements. (b) Identify and explain the reasons for human errors, random errors, and systematic errors in experiments.
13. (a) Light year is a unit of distance used in Astronomy. It is the distance covered by light in one year. Taking the speed of light as $3.0\times10^{8}\text{ m s}^{-1}$, calculate the distance. (b) Calculate the number of seconds in a (a) day, (b) week, and (c) month. State the answers in scientific notation.
14. (a) State the similarities and differences between Vernier Callipers and a micrometer screw gauge. (b) Express the density of mercury given as $13.6\text{ g cm}^{-3}$ in $\text{kg m}^{-3}$.
15.Explain the importance of the SI system.
MCQs Answer Key
- 0.1 mm
- Fear
- 1 mm
- $1\times10^{-4}\text{ m}$
- Outside jaws (A and B)
- Volume of a solid
- Temperature
- cd
- Incorrect position of eye
- Positive zero error
- 1 mm
- Micrometer screw gauge
- 2.0 cm
- 50
- $10^{-3}$
- Distance
- To measure depths of hollow objects
- If they have the same exponents
- $1.0\times10^{-4}\text{ m}$
- Take several readings by looking from more than one direction
- Pierre Vernier
- $10^{-15}\text{ m}$
- Ampere x second
- $10^{3}$
- One-ten thousandths of a second
- Seven
- Mole
- 1 mm
- Newton
- Micrometer Screw Gauge
- $1.38\times10^{8}\text{ km}$
- 0.01 mm
- To represent very large or very small numbers concisely
- 0.05 mm
- Parallax error
- To make units simple to write
- Meaningless
- A widely accepted standard quantity
- It is the only unit with a prefix
- The smallest measurement it can take accurately
- $5\times10^{2}\text{ m}$
- Litres
- Compound prefixes are not allowed
- Anger
- 1 mm to several metres
- 1 to 9
- 0.5 mm
- Pascal
- A quantity that can be measured directly or indirectly using tools and instruments
- 1961
- Metre Rule
- 3.47 cm
- Ampere
- 9 mm
- 0.01 mm
- In lowercase
- Second
- Moved to the left
- It is subtracted from the observed measurement
- Colour
- Science
- Candela