Subject Experts Solutions for Chapter: Machines and Tools, Exercise 2: PRACTICE QUESTIONS (COMPETITION WING)

Venkat went to a factory where he saw hot metallic square plates. He measured the surface area of the hot plates. How did he do it?

What is the use of spring in a tin cutter?

Using a vice, a metal coin of thickness $2.7 \mathrm{cm}$ is to be held firmly. The movable jaw of the vice moves through a distance of $9 \mathrm{mm}$ for one complete rotation of the handle. Calculate the number of times the handle is to be rotated, so that the coin is held firmly.

Rahul by using a hacksaw blade, was cutting metal pipes to supply water to his house. What will happen if he starts moving the hacksaw blade very fast over the metal, due to lack of time?

Why does an axe have a curved sharp edge?

A circular plate at room temperature has a radius of $6.8 \mathrm{cm}$. When it is heated, its area becomes $154 {\mathrm{cm}}^2$. What is the increase in radius? Suggest a method to measure the radius of the plate when it is hot.

What are the advantages and disadvantages of using a vice?

Komali found that most of the agricultural tools her father uses are made up of wood. Explain why it is so.