CBSE Test Paper 04
Chapter 2 Units and Measurements
1. Dimensional analysis can be used to 1
a. check the validity of an equation
b. deducing relations among the physical quantities
c. To check integration of the equation
d. check the order of an equation
2. The surface area of a solid cylinder of radius 2.0 cm and height 10.0 cm in is equal
to 1
a. 15
b.
c. 150
d. 1500
3. The relative error is given by 1
a.
b.
c.
d.
4. When two quantities are multiplied or divided, the relative error in the result is 1
a. the difference of the absolute errors in the multipliers
b. the sum of the absolute errors in the multipliers
c. the difference of the relative errors in the multipliers
d. the sum of the relative errors in the multipliers
5. The number of significant digits in 6.032 N m-2 is 1
a. 6
b. 3
c. 4
d. 5
6. Human heart is an inbuilt clock. Comment. 1
7. Find the relative error in Z, if Z = A4B1/3CD3/2. 1
8. A student measures the thickness of a human hair by looking at it through a microscope
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, 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 on the
thickness of hair? 1
9. The mass of a box measured by a grocer's balance is 2.300 kg. Two gold pieces of masses
20.15 g and 20.17 g are added to the box. What is (a) the total mass of the box, (b) the
difference in the masses of the pieces to correct significant figures? 2
10. A LASER is a source of very intense, monochromatic, and unidirectional beam of light.
These properties of a laser light can be exploited to measure long distances. The distance
of the Moon from the Earth has been already determined very precisely using a laser as a
source of light. A laser light beamed at the Moon takes 2.56 s to return after reflection at
the Moon's surface. How much is the radius of the lunar orbit around the Earth? 2
11. The resistance of a metallic wire is given by R = V/I, where V is the potential difference
and I is the current. In the circuit, the potential difference across the resistance is V = (8 ±
0.5) V and current in the circuit I = (4 ± 0.2) A. What is the value of resistance with its
percentage error? 2
12. Consider a simple pendulum, having a bob attached to a string, that oscillates under the
action of the force of gravity. Suppose that the period of oscillation of the simple
pendulum depends on 3
i. mass m of the bob,
ii. length l of the pendulum and
iii. acceleration due to gravity g at the place.
Derive the expression for its time period using method of dimensions.
13. Two resistors of resistances R1 =(100 ± 3) and R2 =(200 ± 4) are connected (i) in series,
(ii) in parallel. Find the equivalent resistance of the (i) series combination (ii) parallel
combination. 3
14. The wavelength associated with a moving particle depends upon its mass m, its velocity
v and Planck’s constant h. Show dimensional relation between them. 3
15. i. The earth-moon distance is about 60 times the earth radius. What will be the diameter
of earth (approximately in degrees) as seen from the moon. diameter from the earth.
What must be the relative
ii. Moon is seen to be of ( )o size of the moon as compared to the earth.
iii. From parallax measurement, the sun is found to be at a distance of about 400 times of
earth-moon distance. Estimate the ratio of sun-earth diameters. 5
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Chapter 2 Units and Measurements
1. Dimensional analysis can be used to 1
a. check the validity of an equation
b. deducing relations among the physical quantities
c. To check integration of the equation
d. check the order of an equation
2. The surface area of a solid cylinder of radius 2.0 cm and height 10.0 cm in is equal
to 1
a. 15
b.
c. 150
d. 1500
3. The relative error is given by 1
a.
b.
c.
d.
4. When two quantities are multiplied or divided, the relative error in the result is 1
a. the difference of the absolute errors in the multipliers
b. the sum of the absolute errors in the multipliers
c. the difference of the relative errors in the multipliers
d. the sum of the relative errors in the multipliers
5. The number of significant digits in 6.032 N m-2 is 1
a. 6
b. 3
c. 4
d. 5
6. Human heart is an inbuilt clock. Comment. 1
7. Find the relative error in Z, if Z = A4B1/3CD3/2. 1
8. A student measures the thickness of a human hair by looking at it through a microscope
1/7
, 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 on the
thickness of hair? 1
9. The mass of a box measured by a grocer's balance is 2.300 kg. Two gold pieces of masses
20.15 g and 20.17 g are added to the box. What is (a) the total mass of the box, (b) the
difference in the masses of the pieces to correct significant figures? 2
10. A LASER is a source of very intense, monochromatic, and unidirectional beam of light.
These properties of a laser light can be exploited to measure long distances. The distance
of the Moon from the Earth has been already determined very precisely using a laser as a
source of light. A laser light beamed at the Moon takes 2.56 s to return after reflection at
the Moon's surface. How much is the radius of the lunar orbit around the Earth? 2
11. The resistance of a metallic wire is given by R = V/I, where V is the potential difference
and I is the current. In the circuit, the potential difference across the resistance is V = (8 ±
0.5) V and current in the circuit I = (4 ± 0.2) A. What is the value of resistance with its
percentage error? 2
12. Consider a simple pendulum, having a bob attached to a string, that oscillates under the
action of the force of gravity. Suppose that the period of oscillation of the simple
pendulum depends on 3
i. mass m of the bob,
ii. length l of the pendulum and
iii. acceleration due to gravity g at the place.
Derive the expression for its time period using method of dimensions.
13. Two resistors of resistances R1 =(100 ± 3) and R2 =(200 ± 4) are connected (i) in series,
(ii) in parallel. Find the equivalent resistance of the (i) series combination (ii) parallel
combination. 3
14. The wavelength associated with a moving particle depends upon its mass m, its velocity
v and Planck’s constant h. Show dimensional relation between them. 3
15. i. The earth-moon distance is about 60 times the earth radius. What will be the diameter
of earth (approximately in degrees) as seen from the moon. diameter from the earth.
What must be the relative
ii. Moon is seen to be of ( )o size of the moon as compared to the earth.
iii. From parallax measurement, the sun is found to be at a distance of about 400 times of
earth-moon distance. Estimate the ratio of sun-earth diameters. 5
2/7
