BITSAT Physics Units and Measurements MCQs

Question: In the formula X = 3 YZ² ,X and Z have dimensions of capacitance and magnetic induction respectively. The dimensions of Y in MKSA system are :

• a) [M^–3L^–2T^–2A^–4]
• b) [ML^–2]
• c) [M^–3L^–2A⁴T⁸]
• d) [M^–3L²A⁴T⁴]

Answer: [M^–3L^–2A⁴T⁸]

Question: The frequency of vibration of string is given by Here p is number of segments in the string and l is the length. The dimensional formula for m will be

• a) [M⁰LT^–1]
• b) [ML⁰T^–1]
• c) [ML^–1T⁰]
• d) [M⁰L⁰T⁰]

Answer: [ML^–1T⁰]

Question: How many significant figures are there in 0.30100?

• a) 1
• b) 3
• c) 5
• d) None of these

Answer: 5

Question: In the relation P is pressure, Z is distance, k is Boltzmann constant and θ is the temperature. The dimensional formula of β will be

• a) [M⁰L²T⁰]
• b) [M¹L²T¹]
• c) [M¹L⁰T^–1]
• d) [M⁰L²T^–1]

Answer: [M⁰L²T⁰]

Question: Which of the following is most accurate?

• a) A screw gauge of least count 0.001 mm
• b) A screw gauge having pitch 1 mm and 50 divisions on circular scale
• c) A vernier callipers of least count 0.01 mm
• d) Vernier callipers having 20 divisions on the sliding scale (vernier scale) coinciding 19 divisions on the main millimetre scale

Answer: A screw gauge of least count 0.001 mm

Question: The dimensional formula for strain is same as that of

• a) Thrust
• b) Angle
• c) Modulus of elasticity
• d) Stress

Answer: Angle

Question: What is the unit of magnetic permeability?

• a) Wb A^–1 m^–1
• b) Wb^–1 Am
• c) Wb A m^–1
• d) Wb A^–1 m

Answer: Wb A^–1 m^–1

Question: Find the value of  with due regard for significant figures

• a) 0.961
• b) 0.123
• c) 0.921
• d) 0.913

Answer: 0.961

Question: The SI unit of the inductance, the henry cannot be written as

• a) weber/ampere
• b) volt-second/ampere
• c) joule/(ampere)²
• d) ohm-meter

Answer: ohm-meter

Question: Which of the following group have different dimension?

• a) Potential difference, EMF, voltage
• b) Pressure, stress, Young’s modulus
• c) Heat, energy, work done
• d) Dipole moment, electric flux, electric field

Answer: Dipole moment, electric flux, electric field

Question: Which of the following quantities has a unit but dimensionless?

• a) Strain
• b) Reynold’s number
• c) Angular displacement
• d) Poisson’s ratio

Answer: Angular displacement

Question: The dimensional formula for strain is same as that of

• a) Thrust
• b) Angle
• c) Modulus of elasticity
• d) Stress

Answer: Angle

Question: How many significant figures are there in 0.30100?

• a) 1
• b) 3
• c) 5
• d) None of these

Answer: 5