Subject Experts Solutions for Chapter: Test Paper (Chapters 5 to 8), Exercise 1: Test Paper- 2 (Chapters 5 to 8)

What is the role of earth wire in electrical connections?

Determine the refractive index of a medium if the speed of light in the medium is $1.8 \mathrm{x} {10}^8 \mathrm{m}/\mathrm{s}$. [Take speed of light in air$=3\times {10}^8 \mathrm{m} {\mathrm{s}}^{-1}$]

Determine the focal length of a concave mirror which has a radius of curvature equal to $20 \mathrm{cm}$. 

A man hears two sound waves - one of time period $0.1 \mathrm{s}$ and other of $0.5 \mathrm{s}$. Which one will he perceive to be of higher pitch? 

Four bulbs of $60 \mathrm{W}$ each, three fans of $40 \mathrm{W}$ each, a television of $100 \mathrm{W}$ and an air conditioner of $1.1 \mathrm{kW}$ are used for $8$ hours, $6$ hours, $2$ hours and $1$ hour respectively by a family per day. Calculate the cost of electricity used by the family in the month of March at the rate of $₹ 2$ per unit. 

Look at the following figure and answer the given question.

Arrange the mediums in the order of increasing refractive index. 

Look at the following figure and answer the given question.

Which medium is the most optically dense medium? 

Look at the following figure and answer the given question.

Why does the ray of light bend towards the normal while passing from medium $\mathrm{A}$ to medium $\mathrm{B}$?