Class-11 Physics 1 UNITS AND MEASUREMENT

#1. The volume of a cube of side 1 cm is equal to ________ m³.

1 × 10⁻⁶ m³

1 × 10⁻³ m³

1 m³

10⁻⁹ m³

#2. The surface area of a solid cylinder of radius 2.0 cm and height 10.0 cm is equal to ________ mm².

2500 mm²

25000 mm²

1000 mm²

2000 mm²

#3. A vehicle moving with a speed of 18 km/h covers ________ meters in 1 second.

5 m

10 m

3 m

2.5 m

#4. The relative density of lead is 11.3. Its density is g/cm³ or kg/m³.

11.3 g/cm³ or 11300 kg/m³

7.5 g/cm³ or 7500 kg/m³

11.3 g/cm³ or 1130 kg/m³

5.6 g/cm³ or 5600 kg/m³

#5. 1 kg m²/s² = ______ g cm²/s².

100 g cm²/s²

10² g cm²/s²

1000 g cm²/s²

10³ g cm²/s²

#6. 1 m = ______ ly.

3.24078 × 10⁻¹⁷ ly

1.2 × 10⁻¹⁸ ly

1 × 10⁻¹⁶ ly

3.2 × 10⁻¹⁵ ly

#7. 3.0 m/s² = ______ km/h².

1.5 km/h²

10.8 km/h²

3.6 km/h²

15.0 km/h²

#8. G = 6.67 × 10⁻¹¹ N m²/kg² = ______ (cm)³/s² g⁻¹.

6.67 × 10⁻¹² cm³/s² g⁻¹

6.67 × 10⁻⁸ cm³/s² g⁻¹

6.67 × 10⁻⁹ cm³/s² g⁻¹

6.67 × 10⁻¹³ cm³/s² g⁻¹

#9. A calorie is a unit of heat (energy in transit) and it equals about 4.2 J, where 1 J = 1 kg·m²/s². Suppose we employ a system of units in which the unit of mass equals α kg, the unit of length equals β meters, and the unit of time is γ seconds. Show that a calorie has a magnitude of 4.2 α⁻¹ β⁻² γ² in terms of the new units. Which of the following expressions represents the magnitude of a calorie in the new system of units?

4.2 α −1 β −2 γ 2

4.2 𝛼 𝛽 2 𝛾 − 1 4.2αβ 2 γ −1

4.2 α −2 β −1 γ 3

4.2 𝛼 − 1 𝛽 2 𝛾 − 2 4.2α −1 β 2 γ −2

#10. If a new unit of length is chosen such that the speed of light in a vacuum is unity, what is the distance between the Sun and the Earth in terms of the new unit, given that light takes 8 minutes and 20 seconds to cover this distance?

500 units

5000 units

50000 units

50,000 units

#11. Which of the following is the most precise device for measuring length?

a vernier callipers with 20 divisions on the sliding scale

a screw gauge of pitch 1 mm and 100 divisions on the circular scale

an optical instrument that can measure length to within a wavelength of light ?

#12. A student measures the thickness of a human hair by looking at it through a microscope of magnification 100. He makes 20 observations and finds that the average width of the hair in the field of view of the microscope is 3.5 mm. What is the estimate for the thickness of the hair?

0.035 mm

0.35 mm

3.5 mm

35 mm

#13. How can you estimate the diameter of a thread using a meter scale?

Measure the length of the thread and divide by 2.

rap the thread around the meter scale, measure the total length, and divide by the number of turns to find the circumference

Measure the thickness of the thread directly with the meter scale

se the meter scale to measure the diameter directly.

#14. Is it possible to increase the accuracy of a screw gauge arbitrarily by increasing the number of divisions on the circular scale?

Yes, the more divisions, the better the accuracy.

No, increasing divisions improves precision, not accuracy.

Yes, it increases both accuracy and precision.

No, accuracy can be increased only by improving the screw gauge's calibration.

#15. Why does a set of 100 measurements of the diameter of a brass rod provide a more reliable estimate than a set of 5 measurements?

More measurements increase the risk of error.

More measurements average out random errors and provide a more stable result.

More measurements lead to less precision.

More measurements increase the overall measurement error.

#16. The photograph of a house occupies an area of 1.75 cm² on a 35 mm slide. The slide is projected onto a screen, and the area of the house on the screen is 1.55 m². What is the linear magnification of the projector-screen arrangement?

10

50

100

200

What is the number of significant figures in the following values?

#17. 0.007 m²

1

2

3

4

#18. 2.64 × 10²⁴ kg

1

2

3

4

#19. 0.2370 g cm⁻³

2

3

4

5

#20. 6.320 J

2

3

4

5

#21. 6.032 N m⁻²

2

3

4

5

#22. 0.0006032 m

1

2

3

4

Given the length, breadth, and thickness of a rectangular sheet of metal as 4.234 m, 1.005 m, and 2.01 cm respectively, what are the area and volume of the sheet to the correct significant figures?

#23. Area of the sheet

4.261 m²

4.26 m²

4.26117 m²

4.2 m²

#24. Volume of the sheet

0.0853 m³

0.0853464 m³

0.085 m³

0.08 m³

#25. The mass of a box measured by a grocer’s balance is 2.30 kg. Two gold pieces of masses 20.15 g and 20.17 g are added to the box. What is the total mass of the box after the gold pieces are added?

2.34032 kg

2.3403 kg

2.340 kg

2.3403 kg

#26. The two gold pieces have masses of 20.15 g and 20.17 g. What is the difference in their masses, correctly expressed with significant figures?

0.02 g

0.020 g

0.02 g

0.001 g

#27. Select right answer A, B, C, D ?

A

B

C

D

#28. select right answer

A

B

C

D

#29. Select right option

A

B

C

D

#30. When you’re traveling in a fast-moving train, nearby objects (like trees and houses) appear to move rapidly in the opposite direction to the train’s motion, while distant objects (like hilltops, the Moon, and stars) appear to be stationary. Why does this happen?

Nearby objects appear stationary due to the speed of the train, while distant objects move due to the motion of the Earth.

The relative motion of nearby objects is more noticeable because they are closer to you, while distant objects seem to move with the train due to the lack of parallax.

Distant objects appear stationary because they are much farther away, so their motion relative to you is not noticeable due to the limited speed of light.

Distant objects do not appear to move because they are stationary in space, while nearby objects move because of the Earth's rotation.

#31. The Sun is a hot plasma with its inner core at a temperature exceeding 10 7 K 10 7 K and its outer surface at around 6000 K 6000K. Given that the mass of the Sun is 2.0 × 10 30 kg 2.0×10 30 kg and its radius is 7.0 × 10 8 m 7.0×10 8 m, in which range do you expect the mass density of the Sun to lie?

The mass density of the Sun is in the range of densities of solids and liquids.

The mass density of the Sun is in the range of densities of gases.

The mass density of the Sun is near the density of water.

The mass density of the Sun is close to that of lead.

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