1 Which statement defines precision? A How close repeated measurements are to each other B How close a measurement is to the true value C How costly the instrument is D How quickly the measurement is taken
3 Which SI base unit is used to measure the amount of a substance? A Kilogram (kg) B Mole (mol) C Kelvin (K) D Ampere (A)
4 Accuracy refers to how close a measured value is to the: A Accepted or true value B Previous reading C Average of many readings D Smallest scale division
5 Percentage error is calculated by: A (Error ÷ True value) × 100 B (True value ÷ Error) × 100 C (Error + True value) × 100 D (Error − True value) × 100
6 Which of the following best describes a set of measurements that are precise but not accurate? A Close to true value but far from each other B Close to each other but far from true value C Close to true value and close to each other D Far from true value and far from each other
7 When multiplying two measured quantities, the result should be reported with: A The same number of significant figures as the quantity with the fewest significant figures B The maximum number of significant figures in the given values C Any number of significant figures D No significant figures
8 A student measures the mass of a sample five times and gets nearly the same value each time, but the value is far from the true mass. What does this show? A High precision but low accuracy B High accuracy but low precision C High accuracy and high precision D Low accuracy and low precision
9 Which practice reduces parallax error when reading a burette? A Reading the top of the meniscus B Keeping the eye level with the meniscus C Reading from below the meniscus D Reading from far away
10 A student measures the mass of a sample three times and gets 10.2 g, 10.3 g, and 10.1 g. The true mass is 10.5 g. What can be said about the measurements? A They are precise but not accurate. B They are accurate but not precise. C They are both accurate and precise. D They are neither accurate nor precise.
11 Which of the following is a precaution to reduce parallax error while reading a burette? A Look from below the meniscus B Look from above the meniscus C Keep the eye level with the meniscus D Shake the burette before reading
12 Which of the following is an example of a systematic error? A Zero error in a measuring instrument B Random fluctuation in reading a thermometer C Parallax error while reading a burette D Variation due to environmental conditions
13 Which technique is used to reduce parallax error when reading a burette? A Reading from above the meniscus B Keeping the eye level with the meniscus C Shaking the burette before reading D Using a thermometer to measure the liquid
14 Which of the following best explains why significant figures are used in measurements? A To show the uncertainty in the last digit B To make numbers look longer C To hide errors in measurement D To change the unit of the measurement
15 A student reads a burette scale while looking from below the meniscus level (parallax error). This is an example of which type of error? A Systematic error B Random error C Personal error D Zero error
16 Precision describes how close repeated measurements are to: A The true value B Each other C The largest scale mark D The SI unit
17 Which piece of apparatus gives the most precise measurement for volume? A Beaker B Conical flask C Burette D Evaporating dish
18 Which glassware is most suitable for measuring a fixed volume of liquid accurately? A Beaker B Volumetric flask C Test tube D Conical flask
19 A student measures the mass of a sample three times and obtains 2.50 g, 2.51 g, and 2.49 g. The true mass is 2.50 g. These measurements are: A Accurate but not precise B Precise but not accurate C Both accurate and precise D Neither accurate nor precise
20 To reduce parallax error while reading a measuring cylinder, the observer's eye should be: A Above the liquid level B Below the liquid level C Level with the bottom of the meniscus D Far to the side of the cylinder
21 A systematic error is: A Always random B Consistent and affects all readings in the same way C Caused by parallax only D Impossible to detect
22 What is the main purpose of calibrating a thermometer? A To change its size B To make it look shiny C To ensure accurate readings D To increase its weight
23 Parallax error can be reduced by: A Reading the scale from an angle B Keeping the eye level with the meniscus C Shaking the apparatus D Using a larger container
24 A student calculates the percentage error as 2.5%. What does this value indicate? A The measurement is exactly correct. B The error is 2.5% of the true value. C The precision is 2.5%. D The systematic error is 2.5 units.
25 How can parallax error be reduced when reading a burette? A By reading from above B By reading from below C By keeping the eye level with the meniscus D By shaking the burette