11th Physics MCQs Preparation 2022 and Onwards (Unit: Measurements: Set-1 (32 MCQs)) for NMDCAT, ECAT, FPSC, PPSC, JOB Exam, Physics Lecturer, SSC, HSSC (F.Sc.), BS, MS Exams NTS, ETS ETc..
1. The main contribution of modern physics is
(a) Newton's laws of motion,(b) Thermodynamics laws. and (c) Kinetic theory is the contribution of classical Physics up to the end of the 19th century.
2. The branch of physics that deals with the properties and interaction of nuclear particles (protons and neutrons) is called
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3. The fundamental physical quantities which form the basis of the SI units are
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4. Which one of the following is the base physical quantity?
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5. Which list of units contains three base quantities and two derived quantities?
Kelvin, second, and kilogram are the three base quantities, while newton and ohm are the two derived quantities
6. Light year is the unit of
a unit of astronomical distance equivalent to the distance that light travels in one year, which is 9.4607 × 1012 km (nearly 6 million miles).
7. μmｘmm is equal to :
10⁻⁶ m x 10⁻³ m = 10⁻⁹ m²
8. The derived unit joule in terms of base units is
Given: W(Joule) = F x d = ma x d = kg m² s⁻²
9. The scientific notation of a measured value 0.0092 m
By Applying the rules of scientific notation
10. By using Vernier calipers, the length of an object is measured by four students. Which one of the following is correct?
The least count of the vernier caliper is 0.01 cm (two Decimal Places). The least count is the smallest measurement of a device. So 4.51 is the correct
11. What is the absolute precision of the referred result 8.52 cm.?
The precision in the measurement is associated with the least count of the measuring instruments. the decimal point shows that 0.01 is the correct answer
12. The number of significant figures of the value 0.0202 is =
Follow the rules of significant figures
13. Which one of the following measurements is the most significant?
Given: ------------------
14. The length of a body is measured as 3.51 m, if the accuracy is 0.01 m, then the percentage uncertainty in the measurements is
% uncertainty = ( Least count / Measured value) x 100 = (0.01 / 3.51) x 100 = 0.28%
15. The dimensions of the moment of inertia is
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16.. Which pair of physical quantities have the same dimensions?
Work and potential energy have the same unit as Joule. So their dimension are same
17. The dimensions of torque are :
As we know that, Torque T = r x F, Dimension of length r = [L], Dimension of Force = [MLT⁻²], thus dimension of Torque = [L] x [MLT⁻²] = [ML²T⁻²]
18. [M°L°T°] are dimension of
[M°L°T°] is used for dimensionless quantities. So, the correct option is option D. because strain, refractive index, and magnification are all dimensionless quantities (have no units)
19. The precision of the measurement 385,000 km is
In the measurement, the term precision describes the degree of exactness with which a measurement is made and stated (that is the position of the last significant digit). So, in the given measurement 385,000 km the position of the last significant digit (5) is in the thousand places. So, the precision of the measurement in 385,000 km is 1000 km.
20. If 7.635 and 4.81 are two significant numbers. Their multiplication in significant digits is:
According to the rules of a significant figure, when quantities are multiplied or divided, the result has the same of significant figures as the quantity with the smallest numbers of significance. Of the given numbers, 4.81 has the lowest 3 significant figures. So, the result of the calculation should be rounded to the three significant figures. Here We have 7.635 ｘ 4.81 = 36.72435 = 36.7 --Ans Option D. is the correct answer.
21. Compute the result to the correct number of significant digits 1.513 m + 27.3 m =
According to the rules of a significant figure, when two or more quantities are added or subtracted, the result is as precise as the least precise of the quantities. After adding or subtracting, the result should be rounded to the lowest numbers of decimal places as given in the input given number. In the given numbers, 27.3 m has the lowest decimal place (one DP). So, the result of the calculation should be rounded to one decimal place. Here We have 1.513 m + 27.3 m = 28.813 m = 28.8 m ---- Ans
22. How many significant figures does 1.362 + 25.2 have?
According to the rules of significant figures, when two or more quantities are added or subtracted, the result is as precise as the least precise of the quantities. After adding or subtracting, the result should be rounded to the lowest number of decimal places as given in the input given number. In the given numbers 25.2 has the lowest decimal place (one DP). So, the result of the calculation should be rounded to one decimal place. 1.362 + 25.2 = 26.562 = 26.6 (3 significant figures).
23. The number of significant figures in measurement of 0.00708600 are
In decimal fractions, ZEROs to the left of the significant figure are NOT significant and ZEROs to right of the significant figures are significant. So, the correct answer is option C.
24. (2.0 m ± 2.0% )³
The Power is multiplied by the fraction uncertainty So, (2.0 m ± 2.0% )³ = (2.0)³ ± (3 ｘ 2.0%) ) = (8.0 ± 6.0%); Option D. is the correct answer.
25. (5.0 m ± 4.0%) x (3.0 s ± 3.3%)
The fraction uncertainty is added in difference as well as in addition, multiplication, and division. (5.0 m ± 4.0%) x (3.0 s ± 3.3%) = ((5.0 ｘ 3.0 ) ± (4.0% + 3.3%) ) = (15.0 m s ± 7.3%). So, Option B is the correct answer.
The fraction uncertainty is added in difference as well as in addition, multiplication, and division. As given t₁ = (20 ± 0.5) °C and t₂ = (50 ± 0.5) °C. Thus, t₂ - t₁ = (50 ± 0.5) °C - (20 ± 0.5) °C = ((50 - 20 ) ± (0.5 + 0.5) )°C = (30 ± 1 )°C; So, Option C. is the correct answer
the formula for percentage uncertainty is: % uncertainty = ( uncertainty / best estimate ) x 100 = (0.25 / 3.75 ) x 100 = 6.6666 %
By taking the average, the best estimate is 50.0. The first reading will be 49.8 = 50.0 - 0.2 and the second reading 50.2 = 50.0 + 0.2. So, the uncertainty is ± 0.2. therefore, the correct answer is option C.
Option A is wrong because, in units, symbols are used. Option B is wrong because no compound prefixes are used in units. Option C is wrong because the unit of mass starts with small letters kg according to the Bureau Internationale des Poids et des Measures. Option D is correct because the units are spaced and written properly
1 micro = 1/1000000 = 0.000001
The fraction uncertainty is added in difference as well as in addition, multiplication, and division. (5.0 m ± 4.0%) x (3.0 s ± 3.3%) = ((5.0 ｘ 3.0 ) ± (4.0% + 3.3%) ) = (15.0 m s ± 7.3%). So, Option B is the correct answer.
26. The temperatures of two bodies measured by a thermometer are t₁ = (20 ± 0.5) °C and t₂ = (50 ± 0.5) °C. The temperature difference and the error therein are:
The fraction uncertainty is added in difference as well as in addition, multiplication, and division. As given t₁ = (20 ± 0.5) °C and t₂ = (50 ± 0.5) °C. Thus, t₂ - t₁ = (50 ± 0.5) °C - (20 ± 0.5) °C = ((50 - 20 ) ± (0.5 + 0.5) )°C = (30 ± 1 )°C; So, Option C. is the correct answer
27. The percent uncertainty in the measurement of ( 3.76 ± 0.25) m is :
the formula for percentage uncertainty is: % uncertainty = ( uncertainty / best estimate ) x 100 = (0.25 / 3.75 ) x 100 = 6.6666 %
28. A student measures a distance several times. The readings lie between 49.8 cm and 50.2 cm. This measurement is best recorded as
By taking the average, the best estimate is 50.0. The first reading will be 49.8 = 50.0 - 0.2 and the second reading 50.2 = 50.0 + 0.2. So, the uncertainty is ± 0.2. therefore, the correct answer is option C.
29. Which of the following is the CORRECT way of writing units?
Option A is wrong because, in units, symbols are used. Option B is wrong because no compound prefixes are used in units. Option C is wrong because the unit of mass starts with small letters kg according to the Bureau Internationale des Poids et des Measures. Option D is correct because the units are spaced and written properly
30. The metric prefix for 0.000001 is
1 micro = 1/1000000 = 0.000001
31. 1⁰ = -------------
As we know that 57.3° = 1 radian; by unitary method; 1° = 1/57.3 radian = 0.01745 radian
As we know that in one complete revolution of hour hand there are 12 hours, and is also equal to 2𝛑 radians. So, by unitary method 12 hours = 2𝛑 radians, 1 hour = 2𝛑/12 radians, 1 hour = 𝛑/6 radians, 5 hours = 5𝛑/6 radians, by putting the value of 𝛑, 5 hours = 5 (3.14159) /6 radians, = 2.61799 radians, by rounding off to the whole number we get, 3 radians
As we know that 57.3° = 1 radian; by unitary method; 1° = 1/57.3 radian = 0.01745 radian
32. What is the radian measure between the arms of the watch at 5:00 pm?
As we know that in one complete revolution of hour hand there are 12 hours, and is also equal to 2𝛑 radians. So, by unitary method 12 hours = 2𝛑 radians, 1 hour = 2𝛑/12 radians, 1 hour = 𝛑/6 radians, 5 hours = 5𝛑/6 radians, by putting the value of 𝛑, 5 hours = 5 (3.14159) /6 radians, = 2.61799 radians, by rounding off to the whole number we get, 3 radians
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