Question

If the units of length and force are increased four times, then the unit of energy will

• A. increase 8 times
• B. increase 16 times
• C. decrease 16 times
• D. increase 4 times

Answer 1

The correct option is B increase 16 times

We know,
Energy = Force $\times$ length
Simply, $E=F\times L$

But as given, $F^{\prime }=4F$ and $L^{\prime }=4L$, then energy bcomes $E^{\prime }$.
$E^{\prime }=F^{\prime }\times L^{\prime }\Rightarrow E^{\prime }=4F\times 4L=16(F\times L)=16E$
So energy increases 16 times.