Question

A TV tower is $120m$ high. How much more height is to added to it, if its coverage range is to become double?

• A. $120m$
• B. $240m$
• C. $360m$
• D. $480m$

Answer 1

The correct option is C $360m$

Given,

$h=120m$

Coverage range, $d=\sqrt{2Rh}$

The coverage range is double,

$\sqrt{2R{h}^{\prime }}=2\sqrt{2Rh}$

Height of the tower, $h^{\prime }=4h$

The increase in height of length, $480-180=360m$

The correct option is C.