How Does the Right Hand Rule Determine Magnetic Force Direction?

In summary, the right hand rule can be used to determine the direction of the magnetic force on a charged particle entering a magnetic field at an angle. In a series circuit with a battery, resistor, and inductor, the time it takes for the current to reach 50% of its final value can be calculated using the formula I=emf/R(1-e^(-Rt/L)). In a strong electromagnet with a coil placed inside, the average current induced in the coil can be calculated using the formula E=-nbAcos(theta)/T. If the current is parallel to the magnetic field lines, there will be no force.
  • #1
dagg3r
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hi i have a few general questions on the right hand rule,
1. if a charged particle enters a magnetic field going from bottom left to top right at an angle of 45 degrees, and the direction of the current is vertically up how do we determine the force using the right hand rule?

2. a wire which carries a current is placed into a magnetic fileds with right angles to the wires, is there an orientataion for the wire so there would be no magnetic force? I am guessing the the wire to be parallel to the magnetic field?

some electronics questions i got stuck on
1.
A 12.0V battery is about to be connected to a series circuit containing a 10.0 ohm resistor and a 2.00H inductor. after the battery is connected how long will the current rech 50% of its final value?

i did this
.5I = emf/R (1 - e^(-Rt/L))
I=12/10
.6 = (12/10) (1 - e^(-10t/2)) solved for t
t=0.14 seconds

2. A strong electromagnet has a field of 1.60T and a cross sectional area of 0.200m^2. A coil having 200 turns and a total resistance of 20.0 ohm is placed in the electromagnet. If the current in the electromagnet is turned off in 20.0 ms what is the average current induced in the coil?

i used the formula E=-nbAcos(theta)/ T
then having the EMF, worked out the current to be 160 amps? surely i am doing something wrong?
 
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  • #3


The right hand rule is a way to determine the direction of a magnetic force on a charged particle or a current-carrying wire in a magnetic field. It is based on the fact that the magnetic field lines around a current-carrying wire or a magnet form a circular pattern around the wire or magnet.

1. To determine the force on a charged particle using the right hand rule, you would point your right thumb in the direction of the particle's motion, your index finger in the direction of the magnetic field, and your middle finger will point in the direction of the magnetic force.

2. In order to have no magnetic force on a wire in a magnetic field, the wire would need to be parallel to the magnetic field. This is because the angle between the wire and the field would be 0 degrees, and according to the formula F=qvBsin(theta), the force would be 0.

For the electronics questions:

1. Your calculation for the time it takes for the current to reach 50% of its final value looks correct. However, it is important to note that this assumes the inductor is ideal and has no resistance. In reality, there will be some resistance in the inductor which will affect the time it takes for the current to reach 50% of its final value.

2. Your calculation for the average current induced in the coil looks correct. However, it is important to note that this is the maximum current induced in the coil and it will rapidly decrease as the magnetic field decreases. Additionally, the formula you used, E=-nbAcos(theta)/T, is for a rotating coil in a magnetic field, not a stationary one. The correct formula to use in this case would be E=-N(dPhi/dt), where N is the number of turns in the coil and dPhi/dt is the rate of change of magnetic flux through the coil.
 

FAQ: How Does the Right Hand Rule Determine Magnetic Force Direction?

1. What is the right hand rule in magnetism?

The right hand rule in magnetism is a way to determine the direction of the magnetic force acting on a current-carrying wire in a magnetic field. It states that if you point your right thumb in the direction of the current, your fingers will curl in the direction of the magnetic field lines.

2. How do you use the right hand rule to determine the direction of the magnetic force?

To use the right hand rule, point your right thumb in the direction of the current and then curl your fingers towards the direction of the magnetic field. The direction your fingers are pointing is the direction of the magnetic force acting on the current-carrying wire.

3. Why is it called the "right hand" rule?

The right hand rule is called so because it requires the use of your right hand to determine the direction of the magnetic force. If you use your left hand, the direction of the magnetic force will be opposite to the one determined using your right hand.

4. What happens if the current or magnetic field is in a different direction?

If the current or magnetic field is in a different direction, the right hand rule can still be applied. Simply adjust the direction of your thumb and fingers accordingly to determine the correct direction of the magnetic force.

5. Is the right hand rule applicable to all types of magnets?

Yes, the right hand rule is applicable to all types of magnets as long as there is a current-carrying wire and a magnetic field present. It is a fundamental concept in magnetism and is widely used in various applications in science and engineering.

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