2cyv6 q.56. in a cold country, in winter ,a lake was freezing slowly. it was observed that it took 2 hours to form a layer of ice 2cm thick on the water surface

2CyV6 Q.56. In a cold country, in winter ,a lake was freezing slowly. It was observed that it took 2 hours to form a layer of ice 2cm thick on the water surface. Assuming a constant thermal conductivity throughout the layer, the thickness of ice would get doubled after ITIFR-2015] (b) 4 more hours (a) 2more hours (c) 6 more hours (d) 8 more hours f Abeaa nan.