A current of 2A passes through 12V electric bulb . The electrical energy consumed by the bulb in 20 min is?

Assuming that you're truly running the bulb with 12 volts . . .

(2 amperes) x (12 volts) = 24 watts = 24 joules per second

(24 joules/second) x (60 seconds/minute) x (20 minutes) = 28,800 joules

Also, in electric-bill terms ... 0.008 kilowatt-hour