Which of the following is a **fundamental physical quantity**?
A
Velocity B
Force C
Time D
Work
Analysis & Theory
**Time** is a fundamental physical quantity; it cannot be derived from other quantities.
Which of these is a **derived quantity**?
A
Mass B
Length C
Temperature D
Speed
Analysis & Theory
**Speed** is derived from fundamental quantities: speed = distance/time.
The SI unit of **force** is:
A
Dyne B
Kilogram C
Newton D
Joule
Analysis & Theory
**Newton (N)** is the SI unit of force. 1 N = 1 kg·m/s².
Which of the following is a **fundamental unit** in SI system?
A
Joule B
Ampere C
Watt D
Newton
Analysis & Theory
**Ampere** is a fundamental unit for measuring electric current.
Which is a **sub-multiple unit** of meter?
A
Kilometer B
Centimeter C
Decameter D
Megameter
Analysis & Theory
**Centimeter** (cm) is a sub-multiple of meter (1 cm = 10⁻² m).
Which is a correct **dimensional formula** for velocity?
A
[L⁰M⁰T⁰] B
[L¹T⁻¹] C
[M¹L⁻¹T²] D
[L²T]
Analysis & Theory
Velocity = distance/time ⇒ dimensional formula is **[L¹T⁻¹]**.
Which of the following is a **dimensionless quantity**?
A
Pressure B
Strain C
Volume D
Velocity
Analysis & Theory
**Strain** is a ratio and has **no dimension** (dimensionless quantity).
Which of the following is **not** a valid application of dimensional analysis?
A
Checking correctness of formula B
Converting units C
Finding numerical constants D
Deriving relations among physical quantities
Analysis & Theory
**Dimensional analysis** cannot help in finding **numerical constants** or converting between unit systems.
One of the **advantages of SI units** is:
A
They are based on old English system B
They are different for each country C
They are globally accepted and based on powers of 10 D
They use complicated conversions
Analysis & Theory
**SI units** are globally accepted and **decimal-based**, making conversions easier.
A force of 10 N acts on a body of mass 2 kg. Find the acceleration.
A
5 m/s² B
0.2 m/s² C
20 m/s² D
12 m/s²
Analysis & Theory
Using F = ma ⇒ a = F/m = 10/2 = **5 m/s²**.