Free Measurements MCQs with Answers

11. The CORRECT scientific notation for 100.00 is

• A. 1.00 x 10^-3
• B. 1.00 x 10^-2
• C. 1.00 x 10^2
• D. 1.00 x 10^3

Explanation: The correct scientific notation for 100.00 is1.00 × 103because scientific notation requires expressing a number as a product of a coefficient (between 1 and 10) and a power of ten. Here, 1.00 is the coefficient, and the power of ten indicates how many places the decimal must move to recreate the original number. Moving the decimal three places to the right from 1.00 results in 100.00. Option A and B represent much smaller numbers (0.001 and 0.01, respectively), and Option C represents 100, not 100.00, thus not accurately reflecting the decimal precision.

12. The type of error, which is produced by a faulty measuring instrument is called

• A. Logical error
• B. Random error
• C. Personal error
• D. Systematic error

Explanation: The correct answer is systematic error. Systematic errors are errors that consistently occur in the same direction whenever a particular measurement is made. This type of error can be caused by a faulty measuring instrument, such as a scale that is not calibrated correctly. In contrast, logical errors are related to incorrect reasoning, random errors are unpredictable fluctuations, and personal errors are due to human mistakes. Understanding the source of error is crucial in scientific measurement and experimentation.

13. The multiplication product of 20.21 with 20.22 upto four significant figures is

• A. 408.6
• B. 408.64
• C. 408.6462
• D. 409.0

Explanation: To solve this problem, multiply 20.21 by 20.22 to get approximately 408.6442. To express this result with four significant figures, round it to 408.6. Option A is correct because it uses four significant figures. Option C is incorrect because it does not round the result and exceeds four significant figures. Option D rounds the result to a whole number, which doesn't meet the requirement for four significant figures.

14. In a champions' trophy of dart match, a player was given three chances to hit the centre target with darts. He managed to hit all the darts close to each other but away from the centre.The given case depicts that the player's shots were

• A. Precise
• B. Accurate
• C. Uncertain
• D. Unreliable

Explanation: The correct answer is precise. Precision in measurements or actions means the results are consistent or close to each other, regardless of whether they are close to the target. In this scenario, the player's shots were consistently grouped together, which demonstrates precision. Accuracy, on the other hand, is about how close those shots are to the intended target. Since the shots were away from the center, they were not accurate. The terms 'uncertain' and 'unreliable' do not apply here because the shots were consistent, indicating reliability and certainty in the result.

15. The given diagram shows two different scales on a Vernier callipers. The reading on the Vernier scale is

• A. 0.5
• B. 5
• C. 6.5
• D. 7

Explanation: Read the main scale reading (MSR):Observe the mark on the main scale that is just before the zero mark of the Vernier scale. In the given diagram, the zero mark of the Vernier scale is past the 6.5 cm mark on the main scale but before the 6.6 cm mark. Therefore, the MSR is 6.5 cm.2. Read the Vernier scale coincidence (VSC):Find the mark on the Vernier scale that perfectly aligns with any mark on the main scale. In the diagram, the 5th division of the Vernier scale aligns with a mark on the main scale. So, the VSC is 5.3. Calculate the least count (LC):The least count of a Vernier caliper is typically 0.01 cm (assuming 10 divisions on the Vernier scale match 9 divisions on the main scale, and the smallest division on the main scale is 0.1 cm).4. Calculate the total reading:The total reading is given by the formula: Total Reading = MSR + (VSC × LC).Total Reading = 6.5 cm + (5 × 0.01 cm) = 6.5 cm + 0.05 cm = 6.55 cm.

16. Which of the given sources of errors will NOT affect your readings while handling the Gravesand's apparatus?

• A. Friction in the pulleys
• B. Use of rusty holding pins
• C. Use of inaccurate weights
• D. Placement of the drawing board

Explanation: Friction in the pulleys is the correct answer because it directly impacts the smooth movement of the apparatus, affecting the accuracy of the readings. The other options, such as rusty holding pins, inaccurate weights, and the placement of the drawing board, can all introduce errors but may not necessarily be exclusive to Gravesand's apparatus or have the same direct impact on readings.

17. A student performs an experiment in his college laboratory to determine the specific heat of water by electrical method. At the end of experiment, the graph that he drew betweentemperature (T) and time (t) was incorrect.Which of the following can be a source of error that caused inaccurate reading during his observation?

• A. Loss of heat due to radiation
• B. Large increase in temperature of water
• C. Greater least count of the thermometer
• D. Non-steady voltage of the power supply

Explanation: The correct answer is option C: Greater least count of the thermometer. In experiments involving precise temperature measurements, having a greater least count on the thermometer can introduce errors in the readings, resulting in an incorrect graph. The other options, such as loss of heat due to radiation, large increase in temperature of water, and non-steady voltage of the power supply, are less likely to directly cause inaccuracies in the graph between temperature and time in this specific experimental setup.

18. The different magnitudes of same physical quantities are measured by comparing them to:

• A. Available scale
• B. Standard size
• C. Each other
• D. Other physical quantities

Explanation: When the different magnitudes of certain physical quantities are measured then it should be measured according to a standard measure which is the same for everyone throughout the world. So that the distinguished quantities and the differences in the magnitude can be perfectly measured.

19. The dimensions of volume and acceleration (respectively) are:

• A. LT-1
• B. LT-2 and LT-1
• C. L3 and LT-2
• D. L4 T-1 and LT
• E. LT3 and T2

Explanation: The following is the solution:Volume is equal to L x L x L=L3 Acceleration is equal to the rate of changeof velocity=Velocity/Time; ->Since velocity is equal to Distancetravelled/Time=L/T=LT-1 Plug these units into the formula ofacceleration=LT-1/T=LT-2. Hence the units are: L3 and LT-2

20. The dimensions of acceleration are:

• A. LT-1
• B. LT-2
• C. L3
• D. L2
• E. LT2

Explanation: The following is the solution:Acceleration =Difference of velocity/TimeVelocity =Distance/TimeVelocity =L/TTherefore:Acceleration =LT-1/TAcceleration =LT-2