Question

5

Last name only An exercise machine is made out of a bar ab moving without friction on conducting rails as shown in the figure. A uniform magnetic field with B = 0.25 T is directed into the plane of the page. The man moves the bar back and forth at 2 Hz, with distance in each way. The circuit has a resistance of 0.02 The conducting rails are parallel, and at a distance 3 m apart. (L) **2=3m R = 0.0202 B=0,25 T x xit X X X Indicate the direction of the induced current when the bar ab is moving outward with an instantaneous velocity, u. (., moving to the right) (Don'guess. You must analyse, annotate the figure.) (6) Pind the magnitude and direction of the force, Frag, exerted on the bar by the magnetic feld, B. (Ar to the right.) Por this part, leave the answer in terms of B, w, and L, and R. (c) At each instant, the man exerts only enough force to overcome this magnetic forot, mag Calculate the average rate at which this man is doing work. For this part, use the numerical values as given above. (Hint: assume speed, each direction to be constant)

Answer 1

as If it's the sense from the figure, then the current moves upwonds inside the moving conductor ie ba. then f the left conducton moves to the down woord : the current moves ive a In both , ehe electromagnebic force cases, the eleceniony the opposite sense of Vi will have b) F = BIL (B, v and the conductors are ter bo each others I = I = Ber R e = Ber F = Blv R is extracted The speed v 7 » T = -

AX : VT V: VAX - 2 mis . Faser 0.25 121373(2015) -0.022 F: 56:25N C) The man eneres a force to nents a force to set the conducloen in motion. Due to this fonce the second force appears Electromagnetic fonce will always have the opposite sense that g the r. The man exenes a force equal to Fevery time he wants Do change the movement for the conduclor. At the end of im range of movement. The frequency is 2H2