Discussion of Daily Assessment Questions for Class 7 Middle School Science and Measurements Material

There are a discussion the daily assessment questions for class 7 science and measurement material. It questions are not the same as the questions in the daily assessment, but the main questions are the same. There are 10 question with the answer and its explanation. 

Question Number 1

Handi wants to measure the period of a simple pendulum. Which two measuring instruments would be most appropriate for this experiment?

A. Stopwatch and thermometer 
B. Stopwatch and meter ruler 
C. Spring balance and caliper 
D. Vernier calipers and protractor

Answer 

B. Stopwatch and meter ruler 

Explanation 

The period of a pendulum is the time it takes to complete one full swing. To measure the period, you need to measure the time it takes for the pendulum to swing back and forth once. A stopwatch is the ideal instrument for measuring time.

The length of the pendulum also affects its period. Therefore, you need to measure the length of the pendulum. A meter ruler is the most suitable instrument for measuring length in this case.

Question Number 2

Toni is a scientist. He is studying the movement of a planet around the sun. Which skill is he using when she analyzes the planet's position at different points in time and its distance from the sun?

A. Communicating 
B. Observing 
C. Interpreting data 
D. Using space-time relationship

Answer

D. Using space-time relationship

Explanation

The scientist is analyzing how the planet's position and distance change over time. This involves understanding the relationship between space (position and distance) and time. Therefore, she is using the skill of using space-time relationships.

Question Number 3

Two different thermometers are used to measure the temperature of a liquid. The results are as follows:

• Thermometer A reads 27.0 degrees Celsius.
• Thermometer B reads 27.7 degrees Celsius.

The actual temperature of the liquid is 27.7 degrees Celsius.

What conclusion can be drawn from these results?

A. Thermometer B is more sensitive than thermometer A. 
B. Thermometer B is less sensitive than thermometer A. 
C. 27.0 degrees Celsius is more accurate than 27.7 degrees Celsius. 
D. Both readings obtained in the experiment are consistent.

Answer

A. Thermometer B is more sensitive than thermometer A

Explanation

Thermometer B can detect a smaller change in temperature (0.7 degrees Celsius) compared to thermometer A. This indicates that thermometer B is more sensitive.

Question Number 4

The diagram below shows a micrometer screw gauge reading. What is the diameter of the object being measured?

A. 6.05 mm 
B. 6.58 mm 
C. 6.78 mm 
D. 6.88 mm

Answer

C. 6.78 mm 

Explanation

To find the diameter, we add the reading from the main scale and the circular scale.

• Main scale reading: 6.5 mm
• Circular scale reading: 28 divisions * 0.01 mm/division = 0.28 mm

Total diameter = 6.5 mm + 0.28 mm = 6.78 mm

Therefore, the correct answer is C. 6.78 mm 

Question Number 5

Hesti followed the steps below when conducting an experiment in his science laboratory. 
• She filled a beaker partially with water. 

• She weighed a stone with a spring balance and it weighs 0.25 N.
• She dipped the stone into the water in the beaker and weighed it with a spring balance.

What will happen to the weight of the stone dipped in water? 

A.  It will remain as 0.25 N. 
B.  It will be more than 0.25 N. 
C.  It will be less than 0.25 N. 
D.  It will have no weight.

Answer

C.  It will be less than 0.25 N. 

Explanation

The correct answer is C. When an object is submerged in a fluid, it experiences an upward force called buoyancy. This force acts opposite to the weight of the object, effectively reducing its apparent weight.

Question Number 6

Which eye positions would result in a parallax error when measuring the volume of the liquid? What is the correct reading for the volume of the liquid?

Answer

D. P, Q, S 21 ml 

Explanation

A parallax error occurs when the observer's eye is not directly aligned with the meniscus (the curved upper surface of a liquid in a tube). This can lead to an inaccurate reading of the volume.

• Positions P, Q, and S would all result in a parallax error because the observer's eye is not directly aligned with the meniscus.
• Position R is the closest to being directly aligned with the meniscus, but it is still slightly off.
• The correct reading for the volume of the liquid is 21 mL. This is the reading that would be obtained if the observer's eye was perfectly aligned with the meniscus.

Therefore, the correct answer is D. P, Q, S; 21 mL.

Question Number 7

The boiling point of water varies at different altitudes, ranging from 90°C to 140°C. Which of the following Celsius thermometers would give the most accurate reading of the boiling point at different altitudes?

Answer

D

Explanation

The question asks us to select the most suitable thermometer for measuring the boiling point of water at different altitudes.

The boiling point of water is not always 100°C. It varies depending on the atmospheric pressure, which is affected by altitude. Generally, at higher altitudes, the atmospheric pressure is lower, and therefore, the boiling point of water is lower.

Let's analyze each option:

• Option A: This thermometer has a temperature range up to 80°C. If the boiling point of water is higher than 80°C (for example, at lower altitudes), this thermometer will not be able to measure accurately.
• Option B: This thermometer also has a limited temperature range, up to 95°C. Similar to option A, this thermometer will not be able to measure boiling points higher than 95°C.
• Option C: This thermometer has a temperature range from 0°C to 100°C. Similar to option A, this thermometer will not be able to measure boiling points higher than 140°C.
• Option D: This thermometer has a temperature range from 50°C to 150°C. This range is wide enough to measure the varying boiling points of water, from 90°C to 140°C at different altitudes.

Conclusion:

Of the four options, thermometer D is the most suitable for measuring the varying boiling points of water at different altitudes. It has a suitable temperature range and a clear scale, allowing for accurate measurements.

Therefore, the correct answer is D.

Question Number 8

James wants to measure the thickness of a piece of wire. He wrapped the wire around the pencil tightly to a length of 2.1 cm. The wire is wrapped around the pencil with 25 turns of the wire. what is the thickness of the wire?

A. 0.084 cm
B. 0.9 cm
C. 2.1 cm   
D. 12.1 cm

Answer

A. 0.084 cm

Explanation

to calculate the thickness (diameter) of the wire, we need to first determine the length of a single wrap. Since the wire was wrapped 25 times to cover a length of 2.1 cm, the length of one wrap is:

2.1 cm / 25 = 0.084 cm

Question Number 9

The figure shows a footprint found on a wet floor.

What is the estimated area of the footprint? 

A.  8 cm3 
B. 14 cm3 
C. 17 cm3 
D. 22 cm3

Answer

D. 22 cm3

Explanation

To estimate the area of the footprint, we can count the number of complete squares inside the outline of the footprint and then estimate the area of the partial squares.

1. Count the complete squares: Count the number of squares that are entirely within the footprint.
2. Estimate partial squares: For the squares that are only partially covered by the footprint, estimate the fraction of the square that is covered. For example, if half of a square is covered, count it as 0.5.
3. Add up the counts: Add up the number of complete squares and the estimated fractions of squares to get the total area.

Question Number 10

What is the main advantage of using the International System of Units (SI)?

A. It is the most accurate system of measurement. 
B. It is the oldest system of measurement. 
C. It is the most widely used system of measurement. 
D. It is the only system of measurement that is understood globally.

Answer

D. It is the only system of measurement that is understood globally.

Explanation

The International System of Units (SI) is a standardized system of measurement that is used worldwide. This means that scientists, engineers, and other professionals from different countries can communicate and collaborate effectively using SI units, as they are understood and recognized globally.

This eliminates any confusion or misunderstandings that may arise due to the use of different measurement systems in different regions.

• Options A and B: These options are likely too low, as they do not account for all the area covered by the footprint.
• Option C: This option might be slightly too low, depending on how the partial squares are estimated.

Therefore, Option D (22 cm²) is the most likely estimate for the area of the footprint.