Question

In the sketch, a bar is moving to the right at constant speed of 30.0 m/s in a uniform magnetic field of 8.0 T directed into the page. The resistance R is 6.0 . The separation L between the rails is 3.0 m. The bar slides with no friction while making continuous electrical contact with the rails. Find the current flowing in the resistor and the direction of the current.

Answer 1

Complete Question

The diagram for this question is shown on the first uploaded image

Answer:

The current is
`I= 120 A`

the direction is counter clockwise

Step-by-step explanation:

From the question we are told that

The speed of the bar is
`v = 30.0m/s`

The magnetic field is
`B = 8.0 T`

The resistace is
`R = 6.0\ \Omega`

The seperation is
`L = 3.0m`

The induced emf due to the change in magnetic flux as a result of the bar

sliding is mathematically represented as

`\epsilon = -B lv`

Substituting values

`\epsilon =- 8.0 * 30 * 3`

`= - 720V`

According to ohm law

`I = (|\epsilon|)/(R)`

Substituting values

`I = (|-720|)/(6)`

`I= 120 A`

According to Lenz's law the emf should be opposing the magnetic force which produced it so since the magnetic force is moving in the clockwise direction the current due to the emf would be moving in a counter clockwise direction

Answer 2

Step-by-step explanation:

P.d between the ends of the rods is given by

E =vBL = 8*5*3= 120v

To find current V= IR

120v/ 6ohms= 20A

Thus according to lenz law the direction of current is counterclockwise