Jatinder Singh Solutions for Chapter: Practice Papers for Revision, Exercise 9: PRACTICE PAPER - 9

State SI unit of electrical energy.

Calculate the effective resistance between $\mathrm{A}$ and $\mathrm{B}$.

Define watt-hour and kilowatt-hour.

Water in an electric kettle connected to a $220 \mathrm{V}$ supply took $6.5$ minutes to reach its boiling point. How long would it have taken if the supply had been of $200 \mathrm{V}$?

Define the term work function of a metal.

Can a radioactive substance emit both $\alpha$ and $\mathrm{\beta }$ rays simultaneously?

What is meant by alpha emission ?

State three safety precautions while handling the radioactive substances.