12 - Electromagnetic Induction Questions Answers
SIR ANSWER IS given as C could u pls explain?
Two Magnets of M magnetic dipole moment are placed shown in figure. What will be the intensity of magnetism at the point P shown in figure.
the resultant dipole moment is √2M thus the resultant magnetic field is μ2√2M/4πd3 (ans)
A SIMPLE ELECTRIC MOTOR HAS AN ARMATURE RESISTANCE OF 1 ohm & RUNS FROM A D.C SOURCE OF 12V . IT DRAWS A CURRENT OF 2A WHEN UNLOADED . WHEN A CERTAIN LOAD IS CONNECTED TO IT ,IT SPEED REDUCES BY 10% OF ITS INITIAL VALUE ,THE CURRENT DRAWN BY THE UNLOADED MOTOR IS??
ANS 3A
SIR , ISTHE FOLLOWG METH. IS CORRECT
R=1ohm , E=12V , I=2A
I=(E-e)/R => e=10 ON PUTTING D VALUES
NOW AS IT IS REDUCES BY 10% MEANS NOW e' = 9V ( 10/100 X 10 = 1 CHANGE , THUS FINAL = 10-1=9)
I= E-e'/R = ( 12-9)/ 1 = 3A (RESISTANCE IS KEPT CONST.) RESISTANCE WILL CHANGE OR NOT??
yes this method is correct.