Class 11 Physics Chapter 2 Units and Measurements Solved Questions and Answers

1 The density of the material of a cube is measured by measuring its mass and length of its side. If the maximum errors in the measurement of mass and the length are 3% and 2% respectively, the maximum error in the measurement of density is:

A 1%

B 5%

C 7%

D 9%

View Answer

Answer:9%

2 The dimensional formula of kinetic energy is the same as that of:

A pressure

B work

C momentum

D force

View Answer

Answer:work

3 The kilowatt hour is a unit of:

A Energy

B electric charge

C Force

D electric power

View Answer

Answer:Energy

4 The dimensions of h/e (h = Planck’s constant and e = electronic charge) are same as that of:

A magnetic flux

B electric flux

C electric field

D magnetic field

View Answer

Answer:magnetic flux

5 The density of a cube is measured by measuring its mass and length of its sides. If the maximum errors in the measurement of its mass and length are 4% and 3% respectively, the maximum error in density is

A 1%

B 7%

C 5%

D 13%

View Answer

Answer:13%

6 In a resonance tube with tuning fork of frequency 512 Hz, first resonance occurs at water level equal to 30.3 cm and second resonance occurs at 63.7cm. The maximum possible error in the speed is:

A 51.2 cm/sec.

B 102.4 cm/sec

C 204.8 cm/sec

D 153.6 cm/sec

View Answer

Answer:204.8 cm/sec

7 A rectangular plate has length (2 0.02)cm ± and width (1 0.01)cm. ± The maximum percentage error in the measurement of its area is:

A 1%

B 2%

C 3%

D 5%

View Answer

Answer:2%

8 If the units of length and force are increased four times, then the unit of energy will:

A Increase 8 times

B Increase 16 times

C Decreases 16 times

D Increase 4 times

View Answer

Answer:Increase 16 times

9 If velocity, force and time are taken to be fundamental quantities find dimensions formula for

A KV^–1FT^–1

B KV^–1FT

C KVF^–1T^–1

D KV^–1F^–1T

View Answer

Answer:KV^–1FT

10 The frequency of vibration f of a mass m suspended from a spring of spring constant k is given by relation of the type xy f=cm^xk^y where c is a dimensionless constant. The values of x and y are:

A 1/2, 1/2

B –1/2, –1/2

C 1/2, –1/2

D –1/2, 1/2

View Answer

Answer:–1/2, 1/2

11 Dimensional formula for latent heat is:

A M⁰L²T^-2

B MLT^-2

C ML²T^-2

D ML²T^-1

View Answer

Answer:M⁰L²T^-2

12 Which of the following sets cannot enter into the list of fundamental quantities in any system of units?

A length, mass, velocity

B length, time, velocity

C length, time, mass

D mass, time, velocity

View Answer

Answer:length, time, velocity

13 Which of the following groups has different dimensions?

A Potential difference, emf, voltage

B Pressure, stress, Young’s modulus

C Heat, energy, work done

D Dipole moment, electric flux, electric field

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Answer:Dipole moment, electric flux, electric field

14 In a particular system, the units of length, mass and time are chosen to be 10 cm, 10 g and 0.1 s respectively. The unit of force in this system will be :

A 0.1 N

B 1 N

C 10 N

D 100 N

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