Jatinder Singh Solutions for Chapter: Practice Papers for Revision, Exercise 5: PRACTICE PAPER - 5

State two characteristics of a primary coil of a step-up transformer when compared to the secondary coil.

A fuse is rated $8 \mathrm{A}$. Can it be used with an electrical appliance of rating $5 \mathrm{kW}$, $220 \mathrm{V}$? Why?

What is background radiation? How can you detect the background radiation?

Draw a cathode ray tube consisting of a heater, a cathode, a cylindrical anode and a deflecting system. Why are materials of low work function preferred as thermionic cathode materials?

What is radioactivity? 

A radioactive substance is oxidized. What change would you expect to take place in the nature of its radioactivity? Give a reason for your answer.

What are beta rays and gamma rays?

Explain briefly what change takes place within the nuclei when beta particles are emitted by a radioactive substance.