Question { Iqra University, 16739 }

how does capacitor oppose sudden chane in voltage?
how does inductor oppose sudden change in current?

Answer

in capacitors current leads.voltage lags.so capacitor oppose the voltage

Question { MAHINDRA, 8155 }

corona happens more in ac or dc?

Answer

corona more in ac because more conductors are used in ac transmition lines

Question { Siemens, 55209 }

why we use star and delta connection?why we donot give the
supply directly?

Answer

first answer is two or three fluxs(torqres) are required for the to rotate the motor and to produce emf in the generator that why we r using three winding connected like star and delta.but single phase motors also used in small applications .and second answer is to reduce the stating speed of the motor .

Question { College School Exams Tests, 23657 }

a room heater is connected in serise with a 100w bulb.if the
100w bulb is replaced by a 40w bulb then the output of the
heater is increase/decrease/remain same?

Answer

out put of the heater decreases because 100watts bulb takes more power then 40 watts bulb. 100 watts produces more heat then 40 watts bulb.

Question { NFCL, 17172 }

what is the principle of generator, motor, and transformer

and explain the definiton of flemings left hand rule , right
hand rule and ohms law

Answer

faraday s laws of electromagnetic induction for the generator
and transformer ,the current carrying conductor placed in the
magnetic field for motor.right hand rule for generator and
left hand rule for motor.both r same.the current is directly
proportional to the potential difference at constant
temperature for ohms law