Observe the heating curve of water

Which of the following represent boiling?

1. OA
2. AB
3. BC
4. CD

A ray of light travels from a medium of refractive index n₁ to a medium of refractive index n₂. If angle of incidence is i and angle of refraction is r, then $\dfrac{\text{sin i}}{\text{sin r}}$ is equal to

1. n₁

2. n₂

3. $\dfrac{\text{n}$2}{\text{n}1}

4. $\dfrac{\text{n}$1}{\text{n}2}

For cooking of food, which of the following types of utensil is most suitable?

1. High specific heat and low conductivity
2. High specific heat and high conductivity
3. Low specific heat and low conductivity
4. Low specific heat and high conductivity

Which of the following is not a representation of electric power?

1. I²R
2. $\dfrac{\text{V}^2}{\text{R}}$
3. VI
4. I²V