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 .
Sahay Sir > Question Answers > 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 .
The walls of a closed cubical box of edge 40 cm are made of a material of thickness 1 mm and thermal conductivity 4×10^−4 cal/s∘C−1. The interior of the box is maintained at 100∘C above the outside temperature by a heater placed inside the box and connected across 400 V dc . Calculate the resistance of the heater.
15
Nov
The walls of a closed cubical box of edge 40 cm are made of a material of thickness 1 mm and thermal conductivity 4×10^−4 cal/s∘C−1. The interior of the box is maintained at 100∘C above the outside temperature by a heater placed inside the box and connected across 400 V dc . Calculate the resistance [...]
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 ?
15
Nov
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 [...]
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 .
15
Nov
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 . An electric motor operating on a 50 V dc supply draws a current of 12 A. If the effenciency of [...]