Sample answer key — Physics & Maths

This answer key has 5 solved questions with step-by-step worked solutions from sample-question-paper.pdf. Use it to check your work and revise faster, or test yourself on the questions below.

Questions & answers (5)

1. 1

   Which of the following is the SI unit of electric current?

   • AVolt
   • Ampere
   • COhm
   • DWatt

   Answer: b

   Solution: The ampere (A) is the SI base unit of electric current. Volt measures potential difference, ohm measures resistance, and watt measures power.
2. 2

   A body starts from rest and accelerates uniformly at $a = 2\,\text{m/s}^2$ for $t = 5\,\text{s}$. Find the distance travelled.

   Answer: $25\,\text{m}$

   Solution: Using $s = ut + \tfrac{1}{2}at^2$ with $u = 0$: $s = \tfrac{1}{2}(2)(5)^2 = 25\,\text{m}$.
3. 3

   State Newton’s second law of motion.

   Answer: The rate of change of momentum of a body is directly proportional to the net force applied, and acts in the direction of that force.

   Solution: In equation form, $F = \dfrac{dp}{dt} = ma$ for constant mass — force equals mass times acceleration.
4. 4

   What is the value of $\displaystyle\int_0^1 2x\,dx$?

   • A$0$
   • $1$
   • C$2$
   • D$\tfrac{1}{2}$

   Answer: $1$

   Solution: $\int_0^1 2x\,dx = \left[x^2\right]_0^1 = 1^2 - 0 = 1$.
5. 5

   True or False: Sound waves can travel through a vacuum.

   Answer: False

   Solution: Sound is a mechanical wave and needs a material medium (solid, liquid, or gas) to propagate. A vacuum has no particles to carry the vibration.