इसके लिए आपकी भावना शक्ति मजबूत होनी चाहिए. To grasp this example, you've to be aware of the experiment of burning fire by concentrating the rays with the lens at 1 place. The situation is exact same in the two. Now it’s time for you to make use of the https://www.youtube.com/watch?v=WG3Cevb_VHM