## A book with many printing errors contains four different

[question] Question. A book with many printing errors contains four different formulas for the displacement y of a particle undergoing a certain periodic motion: (a) $y=a \sin \left(\frac{2 \pi t}{T}\right)$ (b) $y=a \sin v t$ (c) $y=\left(\frac{a}{T}\right) \sin \frac{t}{a}$ (d) $y=(a \sqrt{2})\left(\sin \frac{2 \pi t}{T}+\cos \frac{2 \pi t}{T}\right)$ (a = maximum displacement of the particle, v = speed of the particle. T = time-period of motion). Rule out the wrong formulas on dimensional gro...

## Fill in the blanks

[question] Question. Fill in the blanks (a) The volume of a cube of side $1 \mathrm{~cm}$ is equal to..... $\mathrm{m}^{3}$ (b) The surface area of a solid cylinder of radius $2.0 \mathrm{~cm}$ and height $10.0 \mathrm{~cm}$ is equal to $(\mathrm{mm})^{2}$ (c) A vehicle moving with a speed of $18 \mathrm{~km} \mathrm{~h}^{-1}$ covers... $\mathrm{m}$ in $1 \mathrm{~s}$ (d) The relative density of lead is $11.3 .$ Its density is .... $\mathrm{g} \mathrm{cm}^{-3}$ or .... \$\mathrm{kg} \mathrm{m}^{-...