Unit and Measurement Objective Type Questions & Answers

21 The surface tension of a liquid is 70 dyne/cm. In MKS system its value is?

A 70 N/m

B 7 ✕ 10-2 N/m

C 7 ✕ 102 N/m

D 7 ✕ 103 N/m

View Answer

Answer: 7 ✕ 10-2 N/m

22 One watt hour contains how many joules?

A 3.6 ✕ 108 J

B 3.6 ✕ 102 J

C 3.6 ✕ 103 J

D 10-3 J

View Answer

Answer: 3.6 ✕ 103 J

23 Electron volt is a unit of

A Charge

B Potential difference

C Energy

D Magnetic Force

View Answer

Answer: Energy

24 What is the unit for measuring the amplitude of a sound?

A Decibel

B Coulomb

C Hum

D Cycles

View Answer

Answer: Decibel

25 The sum of the numbers 436.32, 227.2 and 0.301 in appropriate significant figures is

A 663.821

B 664

C 663.8

D 663.82

View Answer

Answer: 664

26 The numbers 2.745 and 2.735 on rounding off to 3 significant figures will give

A 2.75 and 2.74

B 2.74 and 2.73

C 2.75 and 2.73

D 2.74 and 2.74

View Answer

Answer: 2.74 and 2.74

27 You measure two quantities as A = 1.0 m ± 0.2 m, B = 2.0 m ± 0.2 m. We should report correct value for √AB as:

A 1.4 m ± 0.4 m

B 1.41m ± 0.15 m

C 1.4m ± 0.3 m

D 1.4m ± 0.2 m

View Answer

Answer: 1.4m ± 0.2 m

28 Young’s modulus of steel is 1.9 × 1011 N/m2. When expr essed in CGS units of dynes/cm2, it will be equal to (1N = 105 dyne, 1m2 = 104 cm2)

A 1.9 × 1010

B 1.9 × 1011

C 1.9 × 1012

D 1.9 × 1013

View Answer

Answer: 1.9 × 1012

29 The number of significant figures in 600 m is

A 1

B 2

C 3

D 4

View Answer

Answer: 3

30 The mean length of an object is 5 cm. Which of the following measurements is most accurate?

A 4.9 cm

B 4.805 cm

C 5.25 cm

D 5.4 cm

View Answer

Answer: 4.9 cm

31 Which of the following pairs of physical quantities does not have same dimensional formula?

A Work and torque.

B Angular momentum and Planck’s constant

C Tension and surface tension

D Impulse and linear momentum

View Answer

Answer: Tension and surface tension

32 The equation of state of some gases can be expressed as Vander wal equation i.e. (P + a/v2)(V – b) = RT Where P is the pressure, V is the volume, T is the absolute temperature and a, b, R are constants. The dimensions of ‘a’ are:

A [M1L1T-1]

B [M1L-5T1]

C [M2L5T-1]

D [M1L5T-2]

View Answer

Answer: [M1L5T-2]

33 Which of the following pairs has the same dimensions?

A Specific Heat and Latent Heat

B Impulse and Momentum

C Surface Tension and Force

D Moment of Inertia and Torque

View Answer

Answer: Impulse and Momentum

34 The length and breadth of a rectangular sheet are 16.2 cm and 10.1cm, respectively. The area of the sheet in appropriate significant figures and error is

A 164 ± 3 cm2

B 163.62 ± 2.6 cm2

C 163.6 ± 2.6 cm2

D 163.62 ± 3 cm2

View Answer