Jatinder Singh Solutions for Chapter: Practice Papers for Revision, Exercise 7: PRACTICE PAPER - 7

Power of lens is $2.0 \mathrm{D}$. Find the focal length. What kind of lens it is?

Does the focal length of (a) mirror (b) lens change when it is immersed in water?

Find the resistivity and conductivity of a cylinder of length $20.0 \mathrm{cm}$ and area of cross-section of $4\times {10}^{-4} {\mathrm{m}}^2$, if its resistance is $1.5\times {10}^{13} \mathrm{\Omega }$.

What purpose is served by the terminals of a three-way pin plug?

Draw a diagram of socket and label it.

State Faraday's laws of electromagnetic induction.

What is cathode ray tube? Name the main components of it and explain function of each with principle of cathode ray tube.

A nucleus of an element $\mathrm{X}$ which has the symbol ${}_{\mathit{80}}{}^{\mathit{200}}X$ emits an alpha particle and then a beta particle. The final nucleus is ${}_b{}^{a}Y$. Find a and b.