question_answer

Consider the inferences given below in respect of the following current loop of wire kept in a magnetic field B                

(i) The magnitude and direction of force on the element AC of the wire is \[\frac{\sqrt{3}}{2}\] ILB directed into the page

(ii) The magnitude and direction of force on the element AB of the wire is \[\frac{\sqrt{3}}{2}\] ILB directed into the page

(iii) The total force on the loop ABCA is zero

Which of the above is/are not true?

A)  (i) and (ii)           

B)  (ii) only     

C)  (i) and (iii)          

D)  (ii) and (iii)

Correct Answer: B

Solution :

                Force \[F=Bil\sin \theta \]                 \[=Bil\sin \theta \]                 \[=\frac{\sqrt{3}}{2}Bil\] From Fleming left hand rule, the magnitude and direction of force on the element AB of the wire is \[\frac{\sqrt{3}}{2}\] Bil directed into the page.