Magnitude and direction of current

In summary, the conversation discusses the direction of force and current in a conducting wire moving down an incline. The force is opposing the movement and is calculated using the formula F = ILB (N). The gravitational force is also considered, with the question of whether it has a component along the bar in the downward direction. It is determined that it does have a component, and this is compensated by the normal force from the incline. The conversation also mentions the wire sliding down the incline and the calculation for current using the values of gravity, angle, and length.
  • #1
Physicslearner500039
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Homework Statement
A straight piece of conducting wire with mass and length is placed on a friction less incline tilted at an angle Θ from the horizontal . There is a uniform, vertical magnetic field at all points. To keep the wire from sliding down the incline, a voltage source is attached to the ends of the wire. When just the right amount of current flows through the wire, the wire remains at rest. Determine the magnitude and direction of the current in the wire that will cause the wire to remain at rest.
Relevant Equations
F=ILBsin(Θ) (N); F=mg (N)
1597840884752.png

I am struggling with the angles. Since the conducting wire is moving down for it to be stand still, the force should be opposing it, hence the current should be from Right to Left.

1597845054281.png

I am confident of the Force direction and its value is if ## I ## is the current
##F = ILB (N)## since L and B are perpendicular.
The gravitational force is ##mg (N)## which is acting vertically down. From the previous posts i assume if gravitational force is acting vertically down it does not have the other components. I am confused if the gravitational force has a component along the bar in the downward direction? Please advise.
 
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  • #2
Physicslearner500039 said:
I am confused if the gravitational force has a component along the bar in the downward direction?
It has. Sketch and end view to see it: the normal force from the incline is, well, normal to the incline, and compensates part of mg and part of F. The other part of the normal force has to be compensated by the other part of F.
 
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  • #3
Physicslearner500039 said:
I am confused if the gravitational force has a component along the bar in the downward direction?
What is making the wire slide down the incline?
 
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  • #4
Yes now i understand
1597852645802.png

##IBL\cos\theta = mg\sin\theta##
##I = \frac {mg\tan\theta} {BL}## Amps
The ##mg ## component along the X-axis is 0. I got confused with that. Thank You.
 
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1. What is the difference between magnitude and direction of current?

The magnitude of current refers to the amount of electric charge flowing through a conductor per unit time. It is measured in amperes (A). On the other hand, the direction of current refers to the flow of electric charge, which is typically from positive to negative terminals in a circuit.

2. How is the magnitude of current calculated?

The magnitude of current is calculated by dividing the amount of electric charge (measured in coulombs) by the time it takes for the charge to flow (measured in seconds). This can be represented by the equation I = Q/t, where I is the current, Q is the charge, and t is the time.

3. Can the direction of current change in a circuit?

Yes, the direction of current can change in a circuit depending on the type of circuit and the components used. In direct current (DC) circuits, the current flows in one direction only. In alternating current (AC) circuits, the direction of current changes periodically.

4. How does the direction of current affect the behavior of a circuit?

The direction of current affects the behavior of a circuit in terms of the flow of electric charge and the functioning of components. For example, in a simple circuit with a battery and a light bulb, if the direction of current is reversed, the light bulb will not light up as it requires a specific flow of current to function.

5. What is the role of magnitude and direction of current in electromagnetism?

The magnitude and direction of current play a crucial role in electromagnetism. A current flowing through a conductor creates a magnetic field around it, and the direction of the magnetic field is determined by the direction of current. This phenomenon is used in various applications such as electric motors, generators, and transformers.

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