MCQ
Resonance is an example of
- ATuning fork
- ✓Forced vibration
- CFree vibration
- DDamped vibration
Resonance can occur only if external force is applied at same frequency as that of natural frequency, hence it is forced vibration. Option B is correct.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

$(1)$ The relation between $\frac{\Delta f}{f}$ and $\frac{\Delta n}{n}$ remains unchanged if both the convex surfaces are replaced by concave surfaces of the same radius of curvature.
$(2)$ $\left|\frac{\Delta f }{ f }\right|<\left|\frac{\Delta n }{ n }\right|$
$(3)$ For $n =1.5, \Delta n =10^{-3}$ and $f =20 cm$, the value of $|\Delta f |$ will be $0.02 cm$ (round off to $2^{\text {nd }}$ decimal place)
$(4)$ If $\frac{\Delta n }{ n }<0$ then $\frac{\Delta f }{ f }>0$
