See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

Question Stem for Question Nos. 18 and 19 Question Stem A light of wavelength  is incident on a metal sheet of work function  = 2eV. The wavelength  varies with time as  = 3000 + 40t, where  is in Å and t is in second. The power incident on metal sheet is constant at 100 W. This signal is switched on and off for time intervals of 2 minutes and 1 minute respectively. Each time the signal is switched on, the  start from initial value of 3000Å. The metal plate is grounded and electron clouding is negligible. The efficiency of photoemission is 1% (hc = 12400 eVÅ). 18. The time after which photomission will stop is Ans.