# MCQ on units and measurements class 11 pdf | Units and Measurements Class 11 MCQs Questions with Answers

## 1. The base quantity among the following is

(1) Speed
(2) Weight
(3) Length
(4) Area
There are seven base quantities,
(i) Mass
(ii) Length
(iii) Time
(iv) Current
(v) Amount of substance
(vi) Luminous intensity
(vii) Temperature

### 2. Which of the following is not a unit of time?

(1) Second
(2) Minute
(3) Hour
(4) Light year
Light year is the unit of distance
1 light year = 9.46 × 1015 m

### 3. One astronomical unit is a distance equal to

(1) 9.46 × 1015 m
(2) 1.496 × 1011 m
(3) 3 × 108 m
(4) 3.08 × 10¹6 m

(1) Current
(2) Charge
(3) Energy
(4) Power

(1) 20 g
(2) 20.0 g
(3) 20.01 g
(4) 20 × 100 g

(1) 6 cm
(2) 6.5 cm
(3) 5.99 cm
(4) 6.0 cm

(1) N m
(2) mN
(3) nm
(4) N s

### 8. The number of significant figures in a pure number 410 is

(1) Two
(2) Three
(3) One
(4) Infinite
Related: MCQ on Chemical Bonding with Answers Pdf

(1) 0.125%
(2) 2.43%
(3) 4.12%
(4) 2.14%

its volume is
(1) 0.027
(2) 0.054
(3) 0.081
(4) 0.046

### 11. Zero error in an instrument introduces

(1) Systematic error
(2) Random error
(3) Least count error
(4) Personal error

### 12. A packet contains silver powder of mass 20.23 g ± 0.01 g. Some of the powder of mass 5.75 g ± 0.01 g is

taken out from it. The mass of the powder left back is
(1) 14.48 g ± 0.00 g
(2) 14.48 ± 0.02 g
(3) 14.5 g ± 0.1 g
(4) 14.5 g ± 0.2 g
m1 = 20.23 g ± 0.01 g
m2 = (5.75 ± 0.01) g
m1 – m2 = [(20.23 – 5.75) ± 0.02] g
m (14.48 0.02) g

(1) 13.158 g
(2) 13.2 g
(3) 13.16 g
(4) 13.15 g

### 14. We can reduce random errors by

(1) Taking large number of observations
(2) Corrected zero error
(3) By following proper technique of experiment
(4) Both (1) & (3)

(1) Five
(2) Three
(3) Four
(4) Two

### 16. The number of significant figures in the measured value 26000 is

(1) Five
(2) Two
(3) Three
(4) Infinite
The trailing zeros are not significant.
So, only two digits are significant.

### 17. The number of significant zeroes present in the measured value 0.020040, is

(1) Five
(2) Two
(3) One
(4) Three
Zeores appearing between and after non-zero numbers are significant.
0.020040

### 18. The number of significant figures in the measured value 4.700 m is the same as that in the value

(1) 4700 m
(2) 0.047 m
(3) 4070 m
(4) 470.0 m
4.700 Four significant figures.
Also, 470.0 m  four significant figures.

### 19. If a calculated value 2.7465 g contains only three significant figures, the two insignificant digits in it are

(1) 2 and 7
(2) 7 and 4
(3) 6 and 5
(4) 4 and 6
2.7465 g Last two digits are most insignificant.

(1) 2.85
(2) 2.84
(3) 2.80
(4) 2.83

(1) 6.00 m
(2) 5.99 m
(3) 5.95 m
(4) 5.90 m

(1) 16
(2) 8
(3) 4
(4) 7

### 23. The values of a number of quantities are used in a mathematical formula. The quantity that should be most precise and accurate in measurement is the one

(1) Having smallest magnitude
(2) Having largest magnitude
(3) Used in the numerator
(4) Used in the denominator

(1) [MLT–2]
(2) [ML2T–2]
(3) [M–1L2T]
(4) [M L2 T]

### 25. The pair of the quantities having same dimensions is

(1) Displacement, velocity
(2) Time, frequency
(3) Wavelength, focal length
(4) Force, acceleration

(1) 4
(2) 1
(3) 6
(4) 8
41.68 cm

### 27. We can reduce random errors by

(1) Taking large number of observations
(2) Corrected zero error
(3) By following proper technique of experiment
(4) Both (1) & (3)

### 28. The number of significant figures in the measured value 0.0204 is

(1) Five
(2) Three
(3) Four
(4) Two
The non-zero digits after the decimal places are significant.

### 29. The number of significant figures in the measured value 26000 is

(1) Five
(2) Two
(3) Three
(4) Infinite
The trailing zeros are not significant.
So, only two digits are significant.

### 30. The number of significant zeroes present in the measured value 0.020040, is

(1) Five
(2) Two
(3) One
(4) Three
Zeores appearing between and after non-zero numbers are significant.
0.020040

### 31. The number of significant figures in the measured value 4.700 m is the same as that in the value

(1) 4700 m
(2) 0.047 m
(3) 4070 m
Related: Electric current class 10 MCQ Pdf
(4) 470.0 m
4.700  Four significant figures.
Also, 470.0 m four significant figures.

(1) 2 and 7
(2) 7 and 4
(3) 6 and 5
(4) 4 and 6

### 33. The exchange particles responsible for weak interactions are

(1) Gluons
(2) A-mesons
(3) Photons
(4) W and Z bosons
Weak interaction takes place through the exchange of BOSONS  W and Z bosons

### 34. Maxwell unified

(1) Electricity with gravitation
(2) Electricity with magnetism
(3) Electromagnetism with optics
(4) Electromagnetism with weak interaction
Maxwell unified electromagnetism with optics.

### 35. Which of the following is not a derived force?

(1) Tension in a string
(2) van der Waal forces
(3) Nuclear force between proton-proton
(4) Electrostatic force between proton-proton
Electrostatic force between proton-proton is a fundamental force.

### 36. Which one of the following does not experience strong nuclear force?

(1) Leptons
(2) Baryons
(4) Proton
Leptons doesn't experience strong nuclear force.

### 37. Which pair do not have equal dimensions?

(1) Energy and torque (2) Force and impulse
(3) Angular momentum and Planck’s constant (4) Elastic modulus and pressure
Force [MLT–2]
Impulse  [MLT–1]

### 38. The dimensions of Planck’s constant equals to that of

(1) Energy (2) Momentum (3) Angular momentum (4) Power

### 39. The unit of length, velocity and force are doubled. Which of the following is the correct change in the other

units?
(1) Unit of time is doubled
(2) Unit of mass is doubled
(3) Unit of momentum is doubled
(4) Unit of energy is doubled

### 40. Even if a physical quantity depends upon three quantities, out of which two are dimensionally same, then the

formula cannot be derived by the method of dimensions. This statement
(1) May be true
(2) May be false
(3) Must be true
(4) Must be false
This statement is completely correct. If a quantity depends upon two other quantities which are dimensionally
same then formula's validity can be checked but it can't be derived by the method of dimensions.

### 41. A : Absolute error in a physical quantity can be positive, negative or zero.

R : Absolute error is the difference in measured value and true value of physical quantity.
Answer (4) Absolute error is always positive as it is true value measured value 

### 42. A : A unitless physical quantity must be dimensionless.

R : A pure number is always dimensionless.
Answer (2) : If a quantity doesnot have units so definitely it will be dimensionless but reverse is not true.
Pure number also dimensionless.

### 43. A : Absolute error is unitless and dimensionless.

R : All type of errors are unitless and dimensionless.
Absolute error is not dimensionless rather it will having dimensions of the measured quantity.

### 44. A : Higher is the accuracy of measurement, if instrument have smaller least count.

R : Smaller the percentage error, higher is the accuracy of measurement.
Higher accuracy means higher precisions.
So, error will be very smaller.
Low least count means low error and hence high accuracy.

### 45. A : In a measurement, two readings obtained are 20.004 and 20.0004. The second measurement is more

precise.
Related: Work and energy Class 9 MCQs questions with answers
R : Measurement having more decimal places is more precise.

### 46. A : All physically correct equations are dimensionally correct.

R : All dimensionally correct equations are physically correct.
If an equation is physically correct it has to be dimensionally correct also.
But the reverse is not true.

### 47. A : Physical relations involving addition and subtraction cannot be derived by dimensional analysis.

R : Numerical constants cannot be deduced by the method of dimensions.
Those equations carrying multiplication and divisions of physical quantities can be derived but not valid for

### 48. A : If displacement y of a particle executing simple harmonic motion depends upon amplitude a angular

frequency  and time t then the relation y = a sin t cannot be dimensionally achieved.
R : An equation cannot be achieved by dimensional analysis; if it contains dimensionless expressions.
Assertion and reason is correct and correctly explains assertion.

### 49. A : An exact number has infinite number of significant digits.

R : A number, which is not a measured value has infinite number of significant digits.

### 50: Light year is a unit of

(a) time
(b) distance
(c) sunlight intensity
(d) mass

### 51: The dimensional formula for Planck’s constant is

(a) [MLT]
(b) [ML2T-1]
(c)  [M2L2T-1]
(d)  [ML1T-1]
Answer. b) [ML2T-1]   (Hint use E = hν)

### 52: The surface tension of a liquid is 70 dyne/cm. In MKS system its value is?

(a) 70 N/m
(b) 7 ✕ 10-2 N/m
(c) 7 ✕ 102 N/m
(d) 7 ✕ 103 N/m
Answer. b) 7 ✕ 10-2 N/m

(a) Force
(b) Pressure
(c) Work
(d) Momentum

(a) 10-3 kg m-3
(b) 10-2 kg m-3
(c) 10 kg m-3
(d) 103 kg m-3

### 55: One watt hour contains how many joules?

(a) 3.6 ✕ 108 J
(b) 3.6 ✕ 102 J
(c) 3.6 ✕ 103 J
(d) 10-3 J
Answer. c) 3.6 ✕ 103 J

### 56: Which of the following pairs has the same dimensions?

(a) Specific Heat and Latent Heat
(b) Impulse and Momentum
(c) Surface Tension and Force
(d) Moment of Inertia and Torque

### 57: The equation of state of some gases can be expressed as Vander wal equation i.e.

(P + a/v2)(V – b) = RT
Where P is the pressure, V is the volume, T is the absolute temperature and a, b, R are constants. The dimensions of ‘a’ are:
(a)  [M1L1T-1]
(b)  [M1L-5T1]
(c)  [M2L5T-1]
(d)  [M1L5T-2]

### 58: Electron volt is a unit of

(a) Charge
(b) Potential difference
(c) Energy
(d) Magnetic Force

(a) 0.05 cm
(b) 0.5 cm
(c) 5.0 cm
(d) 0.005 cm

### Units and Measurements Class 11 MCQs Questions with Answers

Question 1.
Physical quantities are
(b) quantities such as length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity
(c) quantities such as pounds, dollars and rupees
(d) quantities such as kilos, pounds and gallons
Answer: (b) quantities such as length, mass, time, electric current, thermodynamic temperature, amount of substance, and luminous intensity

#### Question 2. Which of the following pairs has the same dimensions?

(a) specific heat and latent heat
(b) lmpulse and momentum
(c) surface tension and force
(d) moment of lnertia and torque

### Question 3.The dimensions of kinetic energy is

(a) [M 2L2T]
(b) [ML 2T]
(c) [ML 2T-2]
(d) [ML 2T-1]

#### Question 4. A force F is given by F = at + bt², where t is time. What are the dimensions of a and b?

(a) MLT-1 and MLT0
(b) MLT-3 and ML2T4
(c) MLT-4 and MLT1
(d) MLT-3 and MLT-4

#### Question 5. The atmospheric pressure is 106 dyne/cm². What is its value in SI unit?

(a) 105 newton/m²
(b) 106 newton/m²
(c) 104 newton/m²
(d) 103 newton/m²

(a) FA2T
(b) FAT2
(c) FA2T

(a) [WFv]
(b) [WFv-1]
(c) [W-1F -1v]
(d) [WF-1v -1]

(a) force
(b) pressure
(c) work
(d) momentum

#### Question 9. Which of the following groups have different dimensions?

(a) Potential difference, EMF, voltage
(b) Pressure, stress, Youngs modulus
(c) Heat, energy, work done
(d) Dipole moment, electric flux, electric field
Answer: (d) Dipole moment, electric flux, electric field

#### Question 10. ML-1T -2 is the dimensional formula of

(a) magnetic induction
(b) self-inductance
(c) electric potential
(d) electric field

### Units and Measurements Class 11 MCQ Questions Free PDF | MCQ on Units and Measurements Class 11 pdf with Answers

(a) MT-2A-1
(b) MT-1A-2
(c) M-1L-2TA-1
(d) M-1LTA-2

#### Question 12. Electron volt is a unit of

(a) charge
(b) potential difference
(c) energy
(d) magnetic force

(a) 64 m³
(b) 216 m³
(c) 512 m³
(d) 196 m³

#### Question 14. In SI system the fundamental units are

(a) meter, kilogram, second, ampere, Kelvin, mole and candela
(b) meter, kilogram, second, coulomb, Kelvin, mole and candela
(c) meter, Newton, second, ampere, Kelvin, mole and candela
(d) meter, kilogram, second, ampere, Kelvin, mole and lux
Answer: (b) meter, kilogram, second, coulomb, Kelvin, mole and candela

(a) [ML-1T-2]
(b) [MLT-1]
(c) [ML-1T-1]
(d) [ML-2T-2]

(a) 300
(b) 450
(c) 600
(d) 0

#### Question 17. Resolution is

(a) a measure of the bias in the instrument
(b) None of these
(c) the smallest amount of input signal change that the instrument can detect reliably
(d) a measure of the systematic errors
Answer: (d) a measure of the systematic errors

#### Question 18. Absolute error of the measurement is

(a) the difference between the individual measurement and the true value of the quantity cubed.
(b) the difference between the individual measurement and the true value of the quantity squared.
(c) the difference between two individual measurements and their mean
(d) the difference between the individual measurement and the true value of the quantity
Answer: (a) the difference between the individual measurement and the true value of the quantity cubed.

(a) Wb/m²
(b) Henry(H)
(c) H/m²
(d) Weber(Wb)

#### Question 20. Light year is a unit of

(a) time
(b) distance
(c) sunlight intensity
(d) mass

### Q1. Out of the following pairs, which one does not have identical dimensions ?

(a) Angular momentum and Planck’s constant
(b) Impulse and momentum
(c) Moment of inertia and moment of a force
(d) Work and torque
(c) Moment of inertia and moment of a force

(a) Energy
(b) Watt hour
(c) Momentum
(d) Work
(c) Momentum

### Q3. Identify the pair whose dimensions are equal.

(a) Torque and work
(b) Stress and energy
(c) Force and stress
(d) Force and work
(a) Torque and work

### Q4. Dimensions cannot be used to

(a) check dimensional correctness of a formula
(b) convert units
(c) find value of the constant of proportionality in an equation
(d) deduce a relation among physical quantities
(c) find value of the constant of proportionality in an equation

#### Q5. Two physical quantities whose dimensions are not same, cannot be :

(a) multiplied with each other
(b) divided
(c) added or substracted in the same expression
(c) added or substracted in the same expression

(a) e2 – e2
(b) e2 + 2e2
(c) e2 + e2
(d) e2 – 2e2
(b) e2 + 2e2

(a) thirty
(b) five
(c) four
(d) three
(b) five

#### Q8. The most suitable instrument for measuring the size of an atom is.

(a) Electron microscope
(b) Vernier calliper
(c) Optical Microscope
(d) Screw gauge
(a) Electron microscope

(a) 1 %
(b) 2 %
(c) 4 %
(d) No error
(c) 4 %

(a) 5, 1, 2
(b) 4, 4, 2
(c) 5, 1, 5
(d) 5, 5, 2
(a) 5, 1, 2

#### Q11. Choose the correct statement(s)

(a) Topological sort can be used to obtain an evaluation order of a depending graph.
(b) Evaluation order for a dependency graph dicates the order in which the semantic rules are done
(c) Code generation is independent of the order in which the semantic actions are performed
(d) Both (a) and (b)
(d) Both (a) and (b)

(a) 6
(b) 2
(c) 4
(d) 3
(d) 3

#### Q13. Which of the following is not the unit of energy?

(a) watt-hour
(b) electron-volt
(c) N × m
(d) kg × m/sec2
(d) kg × m/sec2

(a) One minute
(b) Half minute
(c) One degree
(d) Half degree
(a) One minute

#### Q15. Electron volt is a unit of

(a) Potential difference
(b) Electric current
(c) Electronic charge
(d) Energy
(d) Energy

(a) 300
(b) 450
(c) 600
(d) 0
(c) 600

#### Q17. Resolution is

(a) a measure of the bias in the instrument
(b) None of these
(c) the smallest amount of input signal change that the instrument can detect reliably
(d) a measure of the systematic errors
(d) a measure of the systematic errors

#### Q18. Absolute error of the measurement is

(a) the difference between the individual measurement and the true value of the quantity cubed.
(b) the difference between the individual measurement and the true value of the quantity squared.
(c) the difference between two individual measurements and their mean
(d) the difference between the individual measurement and the true value of the quantity
(a) the difference between the individual measurement and the true value of the quantity cubed.

(a) Wb/m²
(b) Henry(H)
(c) H/m²
(d) Weber(Wb)
(b) Henry(H)

#### Q20. Light year is a unit of

(a) time
(b) distance
(c) sunlight intensity
(d) mass
(b) distance

#### Q21. Which one of the following pairs of quantities and their units is a proper match?

(a) Magnetic flux – weber
(b) Capacitance – henry
(c) Impulse – N/sec
(a) Magnetic flux – weber

#### Q22. One second is defined to be equal to

(a) 9192631770 periods of the cesium clock
(b) 1650763.73 periods of the cesium clock
(c) 652189.63 periods of the krypton clock
(d) 1650763.73 periods of the krypton clock
(a) 9192631770 periods of the cesium clock

### Class 11 physics MCQs chapter-wise

Chapter 1 : MCQ on Unit and Measurements
Chapter 2 : Mathematical Methods MCQs
Chapter 3. Motion in plane MCQs
Chapter 4 : Laws of Motion MCQs
Chapter 5 : Gravitation MCQs
Chapter 6 : Machanical properties of solids MCQs
Chapter 7 : Thermal properties of  Matter MCQs
Chapter 8 : Sound MCQs
Chapter 9 : Optics MCQs
Chapter 10 : Electrostatics MCQs
Chapter 11 : Electric current through conductors MCQs
Chapter 12 : Magnetism MCQs
Chapter 14 : Electromagnetic waves and communication system MCQs
Chapter 15 : Semiconductors MCQs