# 39 - Magnetism Questions Answers

Joshi sir comment
Joshi sir comment

Inform for any issue

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SIR ANSWER IS given as C could u pls explain?

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Joshi sir comment

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.

Joshi sir comment

the resultant dipole moment is √2M  thus  the resultant magnetic  field is  μ2√2M/4πd3   (ans)

CALCULATE  THE MAGNETIC FIELD  AT THE CENTRE OF SQUARE WIRE OF SIDE (2)1/2cm  AND CARRYING A CURRENT OF 10A.?

Joshi sir comment

method given by BONEY is correct but formula is not correct

it should be B = 4×{ (μ0I) / 4πR } × [sinθ1+ Sinθ2]

two short magnets of equal dipole momet M are fastened perpedicularat their centre.the magnitude of  magnetic feild at adistance d from the centre on the bisector of right angles is?

Asked By: AKANKSHA Solved By: SARIKA
Joshi sir comment

the resultant dipole moment is √2M  thus  the resultant magnetic  field is  μ2√2M/4πd3   (ans)

is impedence as same as resistanace in a circuit // and // are capacitive reactance and inductive reactance constant values(i.e. independant of value of current in ac circuit at any time)  ??

Joshi sir comment

Write the question with correct symbols

yes it is equivalent to resistance for that circuit

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

Asked By: SARIKA SHARMA 15 Day ago

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??

SARIKA SHARMA 15 Day ago