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Sahay Sir > Question Answers > Uncategorised (JEE Advanced Physics by BM Sharma + GMP Solutions) > Two tungsten lamps with resistances R1andR2, respectively , are connected first in parallel and then in series in a lighting circuit of negligible internal resistance. Given R1>R2. (a) Which lamp will glow more brightly when they are connected in parallel ? (b) If the lamps of resistance R1 now burns out, how will the net illumination produced change ? (c ) Which lamp will glow more brightly when they are connected in series ? (d) If the lamp of resistance R2 now burns out and lamp R1 alone is plugged in , will the net illumination increase or decrease ?

Two tungsten lamps with resistances R1andR2, respectively , are connected first in parallel and then in series in a lighting circuit of negligible internal resistance. Given R1>R2. (a) Which lamp will glow more brightly when they are connected in parallel ? (b) If the lamps of resistance R1 now burns out, how will the net illumination produced change ? (c ) Which lamp will glow more brightly when they are connected in series ? (d) If the lamp of resistance R2 now burns out and lamp R1 alone is plugged in , will the net illumination increase or decrease ?

An electric motor operating on a 50 V dc supply draws a current of 12 A. If the effenciency of the motor is 30 % estimate the resistance of the windings of the motor . respectively Two tungsten lamps with resistances R1andR2