How Does the Right-Hand Rule Determine EMF Direction in a Non-Conducting Loop?

[Kathi201]

A long, straight wire is in the same plane as a wooden, non-conducting loop. The wire carries an increasing current I in the direction shown in the figure (the current is pointing in the left direction).

a. there will be no induced emf and no induced current
b. there will be a counterclockwise induced emf, but no induced current
c. there will be a clockwise induced emf, but no induced current
d. there will be a clockwise induced current in the loop
e. there will be a counterclockwise induced current in the loop

How do you figure out the direction of the emf if you know the direction of the current. The direction of the current is to the left so I believe that means it is moving clockwise. Does that mean that the emf is moving clockwise as well?

 

[alphysicist]

A long, straight wire is in the same plane as a wooden, non-conducting loop. The wire carries an increasing current I in the direction shown in the figure (the current is pointing in the left direction).

a. there will be no induced emf and no induced current
b. there will be a counterclockwise induced emf, but no induced current
c. there will be a clockwise induced emf, but no induced current
d. there will be a clockwise induced current in the loop
e. there will be a counterclockwise induced current in the loop

How do you figure out the direction of the emf if you know the direction of the current. The direction of the current is to the left so I believe that means it is moving clockwise. Does that mean that the emf is moving clockwise as well?

The answer here will depend on how the figure is drawn. As a first step, think about the B field prodeced by the wire. Which way is that B field passing through the loop? Once you have that, you can apply Lenz's law to find the direction of the induced emf.

 

[thomate1]

The direction of the induced EMF (electromotive force) and induced current can be determined using the right-hand rule. This rule states that if you point your thumb in the direction of the current, your curled fingers will point in the direction of the magnetic field, and your palm will face the direction of the induced EMF and current.

In this scenario, since the wire is carrying an increasing current to the left, the magnetic field around the wire will be in a counterclockwise direction. This means that the induced EMF and current in the loop will also be in a counterclockwise direction, as determined by the right-hand rule.

Therefore, the correct answer is option b: there will be a counterclockwise induced EMF, but no induced current. The induced EMF will try to oppose the change in the magnetic field caused by the increasing current in the wire, but as the loop is made of non-conducting material, there will be no induced current.

In summary, the direction of the induced EMF and current can be determined using the right-hand rule, and in this scenario, the induced EMF and current will be in a counterclockwise direction.