Q. In an experiment, the length of a rod is measured as 12.0 m with an uncertainty of ±0.5 m. What is the total uncertainty if the length is used in a calculation involving multiplication by 3?
A.
±1.5 m
B.
±0.5 m
C.
±0.75 m
D.
±0.25 m
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Solution
Total uncertainty = 3 * (0.5 m) = ±1.5 m.
Correct Answer:
A
— ±1.5 m
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Q. In an experiment, the mass of an object is measured as 5.0 kg with an uncertainty of ±0.2 kg. What is the absolute error?
A.
0.2 kg
B.
0.5 kg
C.
0.1 kg
D.
0.3 kg
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Solution
Absolute error is the uncertainty in the measurement, which is ±0.2 kg.
Correct Answer:
A
— 0.2 kg
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Q. In an experiment, the measured value of a voltage is 12.0 V with an uncertainty of ±0.2 V. What is the maximum possible error?
A.
0.2 V
B.
0.1 V
C.
0.5 V
D.
0.0 V
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Solution
Maximum possible error is equal to the uncertainty, which is ±0.2 V.
Correct Answer:
A
— 0.2 V
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Q. In an experiment, the voltage is measured as 12.0 V with an uncertainty of ±0.3 V. What is the absolute error in the voltage measurement?
A.
0.3 V
B.
0.25 V
C.
0.5 V
D.
0.1 V
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Solution
The absolute error is given as ±0.3 V.
Correct Answer:
A
— 0.3 V
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Q. In an experiment, the voltage is measured as 12.0 V with an uncertainty of ±0.5 V. What is the absolute error in the voltage measurement?
A.
0.5 V
B.
0.05 V
C.
5 V
D.
1 V
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Solution
The absolute error is given directly as ±0.5 V.
Correct Answer:
A
— 0.5 V
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Q. In an experiment, the voltage is measured as 12.0 V with an uncertainty of ±0.5 V. What is the maximum possible error in the voltage measurement?
A.
0.5 V
B.
0.25 V
C.
1 V
D.
0.1 V
Show solution
Solution
The maximum possible error is the absolute uncertainty, which is ±0.5 V.
Correct Answer:
A
— 0.5 V
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Q. In the calculation 12.11 + 0.3 + 1.234, how many significant figures should the answer have?
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Solution
The answer should have 2 decimal places, as 0.3 has the least precision.
Correct Answer:
C
— 4
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Q. In the context of measurement, what does the term 'accuracy' refer to?
A.
The closeness of a measured value to the true value
B.
The repeatability of measurements
C.
The range of values within which the true value lies
D.
The number of significant figures in a measurement
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Solution
Accuracy refers to how close a measured value is to the true or accepted value.
Correct Answer:
A
— The closeness of a measured value to the true value
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Q. In the context of measurement, what does the term 'precision' refer to?
A.
The closeness of a measurement to the true value
B.
The reproducibility of measurements
C.
The range of values
D.
The average of measurements
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Solution
Precision refers to the reproducibility of measurements, indicating how consistent the results are when repeated.
Correct Answer:
B
— The reproducibility of measurements
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Q. In the expression 0.00450 + 0.0034, how many significant figures should the result have?
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Solution
The result should have 3 significant figures, as 0.0034 has the least precision.
Correct Answer:
B
— 4
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Q. In the measurement 0.007890, how many significant figures are present?
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Solution
The significant figures are 7, 8, 9, and 0, totaling 4 significant figures.
Correct Answer:
C
— 5
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Q. In the measurement 0.03040, how many significant figures are present?
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Solution
In 0.03040, the leading zeros do not count, but the trailing zero after the decimal does. Therefore, there are 4 significant figures.
Correct Answer:
B
— 4
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Q. In the measurement 123.45, how many significant figures are present?
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Solution
All digits in 123.45 are significant, giving a total of 5 significant figures.
Correct Answer:
C
— 5
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Q. In the measurement 150.0, how many significant figures are present?
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Solution
The significant figures are 1, 5, and the trailing zero after the decimal point.
Correct Answer:
C
— 4
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Q. In the measurement 2500 kg, how many significant figures are there?
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Solution
The number 2500 kg has two significant figures unless specified otherwise (e.g., with a decimal point).
Correct Answer:
A
— 2
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Q. In the number 0.0004560, how many significant figures are present?
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Solution
The leading zeros are not significant, but the trailing zero is significant. Therefore, it has 4 significant figures.
Correct Answer:
B
— 4
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Q. In the number 0.007890, how many significant figures are there?
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Solution
The significant figures are 7, 8, 9, and the leading zeros are not counted.
Correct Answer:
C
— 5
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Q. In the number 2500, how many significant figures are there?
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Solution
Without a decimal point, 2500 has 2 significant figures.
Correct Answer:
A
— 2
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Q. In the number 4500, how many significant figures are there?
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Solution
4500 has 2 significant figures unless specified with a decimal point.
Correct Answer:
A
— 2
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Q. In the number 5000, how many significant figures are there?
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Solution
5000 has 1 significant figure unless specified with a decimal point (e.g., 5000.).
Correct Answer:
A
— 1
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Q. The dimensional formula for work is:
A.
[M^1 L^2 T^-2]
B.
[M^1 L^1 T^-1]
C.
[M^0 L^2 T^-1]
D.
[M^1 L^0 T^0]
Show solution
Solution
The dimensional formula for work is [M^1 L^2 T^-2].
Correct Answer:
A
— [M^1 L^2 T^-2]
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Q. The length of a rod is measured as 50 cm with an error of 1 cm. What is the minimum possible length?
A.
49 cm
B.
50 cm
C.
51 cm
D.
48 cm
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Solution
Minimum possible length = Measured value - Error = 50 - 1 = 49 cm.
Correct Answer:
A
— 49 cm
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Q. The temperature is measured as 25°C with an error of 1°C. What is the range of possible true values?
A.
24°C to 26°C
B.
25°C to 27°C
C.
23°C to 25°C
D.
26°C to 28°C
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Solution
True value can be in the range of (Measured value - Error) to (Measured value + Error) = 25°C ± 1°C = 24°C to 26°C.
Correct Answer:
A
— 24°C to 26°C
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Q. The unit of electric charge in SI is?
A.
Coulomb
B.
Ampere
C.
Volt
D.
Ohm
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Solution
The SI unit of electric charge is Coulomb (C).
Correct Answer:
A
— Coulomb
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Q. The unit of energy in the SI system is:
A.
Joule
B.
Calorie
C.
Watt
D.
Newton
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Solution
The SI unit of energy is Joule (J).
Correct Answer:
A
— Joule
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Q. The unit of pressure in SI is:
A.
Pascal
B.
Bar
C.
Torr
D.
Atmosphere
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Solution
The SI unit of pressure is Pascal (Pa), defined as one newton per square meter (N/m²).
Correct Answer:
A
— Pascal
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Q. The unit of pressure in the SI system is:
A.
Pascal
B.
Bar
C.
Torr
D.
Atmosphere
Show solution
Solution
The SI unit of pressure is Pascal (Pa), defined as one newton per square meter (N/m²).
Correct Answer:
A
— Pascal
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Q. The weight of an object is measured as 10 kg with a 0.1 kg error. What is the maximum possible weight?
A.
10.1 kg
B.
10.2 kg
C.
10 kg
D.
9.9 kg
Show solution
Solution
Maximum possible weight = Measured weight + Absolute error = 10 + 0.1 = 10.1 kg.
Correct Answer:
A
— 10.1 kg
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Q. The weight of an object is measured as 200 g with a possible error of 5 g. What is the range of the true weight?
A.
195 g to 205 g
B.
200 g to 205 g
C.
195 g to 200 g
D.
200 g to 210 g
Show solution
Solution
True weight range = Measured value ± Absolute error = 200 ± 5 = 195 g to 205 g.
Correct Answer:
A
— 195 g to 205 g
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Q. What are the dimensions of pressure?
A.
ML^-1T^-2
B.
ML^2T^-2
C.
ML^2T^-1
D.
M^0L^0T^0
Show solution
Solution
Pressure is defined as force per unit area. The dimensions of force are ML^1T^-2, and area is L^2, thus pressure has dimensions ML^-1T^-2.
Correct Answer:
A
— ML^-1T^-2
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Showing 151 to 180 of 298 (10 Pages)
Units & Measurement MCQ & Objective Questions
Understanding "Units & Measurement" is crucial for students preparing for exams. This topic lays the foundation for various scientific concepts and is frequently tested in objective questions. Practicing MCQs and important questions in this area not only enhances your conceptual clarity but also boosts your confidence in exam preparation.
What You Will Practise Here
Fundamental units and derived units
Measurement of length, mass, and time
Conversion of units and dimensional analysis
Significant figures and their importance in measurements
Measurement errors and uncertainty
Applications of units in real-life scenarios
Key formulas related to measurement and conversions
Exam Relevance
The topic of "Units & Measurement" is integral to the curriculum of CBSE, State Boards, NEET, and JEE. It often appears in various formats, including direct questions, numerical problems, and conceptual applications. Students can expect to encounter questions that require them to convert units, apply formulas, and interpret measurements in practical contexts. Familiarity with this topic can significantly enhance your performance in both school and competitive exams.
Common Mistakes Students Make
Confusing between fundamental and derived units
Incorrectly converting units without paying attention to the scale
Neglecting significant figures in calculations
Misunderstanding the concept of measurement errors
Overlooking the application of dimensional analysis in problem-solving
FAQs
Question: What are the basic units of measurement?Answer: The basic units include length (meter), mass (kilogram), and time (second), which are fundamental to all measurements.
Question: How can I improve my accuracy in measurements?Answer: Always use appropriate measuring tools, be mindful of significant figures, and practice converting units accurately.
Ready to enhance your understanding of "Units & Measurement"? Start solving practice MCQs today to test your knowledge and prepare effectively for your exams!
