15 - 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
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.
in the previous case if north pole is brought near the mettalic ring why the direction is reversed. we have to consider the drn of magnetic field of magnet or not. if yes then which drn N-S or S-N.
The south pole of a magnet is bought near a metallic ring ,the direction induced current in the ring will be? Explain it clearly.
If observer is in the side of magnet, then in the given case form S in the ring, it will give you clockwise direction