Question

A circuit consists of a conducting bar of length 60 cm, sliding along two parallel conducting

rails. the bar slides to the left with constant velocity through a 5.40 x 10^-4 t uniform
magnetic field and a velocity of 30 m/s.
a. find the magnitude of emf
b. find the current that passes through the resistor r = 20 ohms.
c. what is the direction of the current m

Answer 1

a.)emf =0.00972 V

b.)I=0.000486 A

c.)the direction of the current would be from right to left.

Step-by-step explanation:

a.) emf= B*L*V

B is the magnetic field strength

L is the length

V is the velocity

Given:

B=5.40 x 10^-4 T

L=60 cm

V=30 m/s

so...

emf = (5.40 x 10^-4 T) (0.6 m) (30 m/s)

the answer is...

emf = 0.00972 V

b.)Use Ohm's law

I = V/R

V is the voltage (emf)

R is the resistance

Given:

V=0.00972 V

R=20 ohms

so...

I = (0.00972 V) ÷ (20 ohms)

the answer is...

I=0.000486 A or 486 microampheres

c.)The direction of the current is determined using the right-hand rule. Based on the given information of the conducting bar sliding to the left through the magnetic field, the induced current would flow from right to left through the resistor.

Answer 2

horizontal, frictionless conducting rails at a constant velocity
v
. The rails are connected at one end with a metal strip. A uniform magnetic field
B
, directed out of the page, fills the region in which the rod moves. Assume that L = 10 cm, v = 5.0 m/s, and B = 1.2 T. What are the (a) magnitude and (b) direction (up or down the page) of the emf induced in the rod? What are the (c) size and (d) direction of the current in the conducting loop? Assume that the resistance of the rod is 0.40Ω and that the resistance of the rails and metal strip is negligibly small. (e) At what rate is thermal energy being generated in the rod? (f) What external force on the rod is needed to maintain
v
? (g) At what rate does this force do work on the rod?