31. Which of the following quantities is dimensionless?

• a) Strain
• b) Angle
• c) Refractive index
• d) All of the above
• Answer: d) All of the above

32. The SI unit of electric charge is:

• a) Coulomb
• b) Ampere
• c) Volt
• d) Ohm
• Answer: a) Coulomb

33. What is the dimensional formula of pressure?

• a) [M L^-1 T^-2]
• b) [M L T^-2]
• c) [M L^-2 T^-2]
• d) [M T^-2]
• Answer: a) [M L^-1 T^-2]

34. The quantity with units of ‘N·m’ is:

• a) Work
• b) Force
• c) Torque
• d) Energy
• Answer: c) Torque

35. Which of the following is not a derived unit?

• a) Joule
• b) Watt
• c) Kilogram
• d) Newton
• Answer: c) Kilogram

36. The principle of dimensional homogeneity states that:

• a) Equations must have the same dimensions on both sides
• b) All physical quantities have dimensions
• c) Only base quantities have dimensions
• d) Derived quantities do not have dimensions
• Answer: a) Equations must have the same dimensions on both sides

37. The SI unit of inductance is:

• a) Henry
• b) Farad
• c) Tesla
• d) Weber
• Answer: a) Henry

38. Which of the following is a fundamental constant?

• a) Speed of light
• b) Gravitational constant
• c) Planck’s constant
• d) All of the above
• Answer: d) All of the above

39. Which of the following is a non-SI unit of pressure?

• a) Pascal
• b) Bar
• c) Torr
• d) All of the above
• Answer: d

40. The dimensional formula of momentum is:

• a) [M L T^-1]
• b) [M L^2 T^-2]
• c) [M T^-2]
• d) [M L T^-2]
• Answer: a) [M L T^-1]