The amplitude of velocity of a particle is given by, ${\mathrm{V}}_{\mathrm{m}}={\mathrm{V}}_0/\left({\mathrm{a\omega }}^2-\mathrm{b\omega }+\mathrm{c}\right)$ where ${\mathrm{V}}_0,\mathrm{a},\mathrm{b},\mathrm{c}$ are positive:

The condition for a single resonant frequency is 

1. ${\mathrm{b}}^2<4\mathrm{ac}$

2. ${\mathrm{b}}^2=4\mathrm{ac}$

3. ${\mathrm{b}}^2=5\mathrm{ac}$

4. ${\mathrm{b}}^2=7\mathrm{ac}$

In a forced oscillation, when the system oscillates under the action of the driving force $\mathrm{F}$ $=$ ${\mathrm{F}}_0$ $\sin$ $\mathrm{\omega t}$ in addition to its internal restoring force, the particle oscillates with a frequency equal to

1.  The natural frequency of the body

2.  Frequency of driving force

3.  The difference in frequency of driving force and natural frequency

4.  Mean of the driving frequency and natural frequency

Given below are two statements: