Question

In this problem, there is a conducting non magnetic bar that is in contact with conducting rails connected to a lightbulb (light bulb reisistance= 12.5 ohms). In this problem friction and air resistance can be ignored. There is a strong magnetic field in the region directed out of the page. The bar reaches a constant speed. The lightbulb used 0.18 W of electrical energy as the bar is falling. the bar has a mass of 650 grams and a length of 84 cm.

A) what is the constant speed of the bar as it is falling?

B) find the direction and magnitude of the current?

C) find the strength of the magnetic field

Bude

Answer 1

classmate Date Page solution Power = 0.185s m=650 h = 84cm 0.84 m R = 12.52 0.65 kg we know, according to Canadays Law é = d OB at at e= doB at B d A dt e=dOR at Bliv Area = ly udt y Also Power e² Resistance en V Power X Resistance e= (0.18 )(1215) 1.5V e= Blue= 1.5 V reachy magnetic New as the red is falling, weight of red is balanced force on ned to constant velocity B I l mg R R Belv mg = R re mg = VIR I = Vee V = Voltage = emaze

classmate Date Page v= mg = e ² VR. ez mg R V- (1.5)(1:5) m/s (0.65) (9.8) (1215) 0.02826 mis to find the direction of Induced current we will see, on falling med the magnetic flux de is nod area is to Induced current accending to lenz law will be such that It will incuase the magnetic fluix and at will curl one Fingers of right hand such a that thumt gives field B sh will co decreasing decuacing magnetic way A Induced o 0 of If current is as shown. anticlockwise!

classmate Date Page I= V LR 12.5 0:12 Amperes We know Va Blv 1.5 B [84X102) (0.02826 Tesla B 184x102) (0-02826) 63.18876 Tesla B