Statement (1) is incorrect. Separated DNA fragments are visualized after staining with a compound like ethidium bromide, followed by exposure to UV radiation. Pure DNA fragments are not directly visible under UV light without staining. The other statements are correct.
A bob of heavy mass \(m\) is suspended by a light string of length \(l\). The bob is given a horizontal velocity \(v_0\) as shown in figure. If the string gets slack at some point P making an angle \( \theta \) from the horizontal, the ratio of the speed \(v\) of the bob at point P to its initial speed \(v_0\) is :