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jdiamonddiva
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[SOLVED] investigating the effect of magnetic force on a current carrying wire
The aim of this experiment is to investigate the magnetic force of a current-carrying wire. In this experiment we will investigate the effect of current and to do this one shall measure the force on a current-carrying wire placed in a uniform magnetic field.
Magnetic field strength is defined as:
‘the force per unit length per unit current on a current-carrying conductor at right angles to the direction of the magnetic field.’
When the charges pass through uniform magnetic field they experience a magnetic force. The total magnetic force on the wire is calculated by
B=F/Il where F = Force in Newtons, B= magnetic field strength measured in Tesla and l = length measured in meters.
The term B is called the magnetic field strength, or the flux density, and is measured in Tesla, T. The magnetic flux density can be thought of as the concentration of field lines. We can increase the force by increasing any of the terms within the equation. If we coil up the wire, we increase its length within the magnetic field
To investigate this further an experiment can be conducted to show the dependence of the force on a current-carrying wire in a magnetic field.
Method explained:
- A ‘u’ shaped magnet is formed by placing two Magnadur magnets on a steel yoke with opposite poles facing each other.
- The magnet is then placed on the top-pan balance and the balance is then zeroed. The ‘top pan balance’ is a straightforward way of investigating the factors affecting
- The force on a wire carrying a current in a magnetic field. The ‘wire’ is clamped so that it remains stationary and the balance measures the ‘change in weight’ of the Magnadur magnets placed on its pan.
- A variable current source is connected to the current balance assembly, which has at one end a removable wire loop etched onto a circuit board. This wire loop is then placed into the permanent magnet assembly so the wire loop is perpendicular to the magnetic field but is not touching the magnets.
- When a current flows through the wire loop, a magnetic force is created. Since the wire loop is stationary the magnetic force acts on the permanent magnet assembly causing its weight to either increase or decrease depending on the direction of the current and the orientation of the magnetic field. The change in the balance reading is due to the magnetic force given by the equation that will be expanded upon later.
- The balance reading is then to be recorded at 0.5 intervals of current (this is altered using the variable resistor)
- One gram is equivalent to a weight of 0.0098 N (0.01 N will probably be accurate enough for this experiment).
Control of Variables
In this experiment it is important to keep variables controlled in order to make this a fair test. There are three variables to consider in this experiment and they are as follows:
1. The length of wire may be varied by exchanging one wire loop for another.
2. The current amplitude may be varied by adjusting the output from the power supply. (The direction of the current flow may also be altered.)
3. The strength of the magnetic field may be altered by varying the number of horseshoe magnets in the magnet assembly. (The direction of the magnetic field may also be altered.)
In this current experiment it is the current that is being investigated and therefore that is the independent variable that will allow us to get different balance readings (dependent variable.) It is important to keep therefore, the length of the wire and the strength of the magnetic field constant. To ensure this I have ensured that there are only two magnadur magnets and that the wire is a set length of 1 metre. It is also important for the wire to have a uniform cross-sectional area, as this increases the surface area of the wire and thus means that the accuracy of the answer will change accordingly
Precautions for accuracy
All school experiments and in fact all experiments conducted by people are all vulnerable to human error and this must be accounted for in order to gain as accurate result as is possible.
In this experiment in order to do this the following was done:
- the temperature of the room was kept note of at all times as to any unusual changes that may effect the experiment, this did not prove to be an issue.
- All balance readings were taken into consideration as +/- 0.01g
- Two readings were taken each time and an average conducted for further accuracy
- The power supply was turned off after each reading to ensure that the wire could return to room temperature after having current passed through it to ensure a more accurate reading.
-
Precautions for safety
1. Caution! A rheostat has been added into the circuit for safety precautions to ensure the current does not get too hot and thus the rod too hot.
2. The power supply should be set to constant current mode. To do so, turn the DC VOLTAGE ADJUST knob fully clockwise, then adjust the DC CURRENT ADJUST knob to obtain the desired output current.
Range and number of readings.
Using an ammeter of range 0 –5 ampere two readings at each 0.5 interval was taken to give a total of 18 readings.
As with all physics laboratory experiments, one must be careful to use the appropriate units. If all forces (i.e., the magnetic force and weight) are measured in Newtons ( ), charges in coulombs ( ), and velocities in meters per second ( ), then as we will see in the explanation the unit of the magnetic field is given as Newton per coulomb-meter per second. In SI units this is known as the tesla ( ).
i have done some results but need help with the graph, conclusion and evaluation just need some guidance could i possibly email my investigation to someone and ask for their hlep? thank you
Homework Statement
The aim of this experiment is to investigate the magnetic force of a current-carrying wire. In this experiment we will investigate the effect of current and to do this one shall measure the force on a current-carrying wire placed in a uniform magnetic field.
Homework Equations
Magnetic field strength is defined as:
‘the force per unit length per unit current on a current-carrying conductor at right angles to the direction of the magnetic field.’
When the charges pass through uniform magnetic field they experience a magnetic force. The total magnetic force on the wire is calculated by
B=F/Il where F = Force in Newtons, B= magnetic field strength measured in Tesla and l = length measured in meters.
The term B is called the magnetic field strength, or the flux density, and is measured in Tesla, T. The magnetic flux density can be thought of as the concentration of field lines. We can increase the force by increasing any of the terms within the equation. If we coil up the wire, we increase its length within the magnetic field
To investigate this further an experiment can be conducted to show the dependence of the force on a current-carrying wire in a magnetic field.
The Attempt at a Solution
Method explained:
- A ‘u’ shaped magnet is formed by placing two Magnadur magnets on a steel yoke with opposite poles facing each other.
- The magnet is then placed on the top-pan balance and the balance is then zeroed. The ‘top pan balance’ is a straightforward way of investigating the factors affecting
- The force on a wire carrying a current in a magnetic field. The ‘wire’ is clamped so that it remains stationary and the balance measures the ‘change in weight’ of the Magnadur magnets placed on its pan.
- A variable current source is connected to the current balance assembly, which has at one end a removable wire loop etched onto a circuit board. This wire loop is then placed into the permanent magnet assembly so the wire loop is perpendicular to the magnetic field but is not touching the magnets.
- When a current flows through the wire loop, a magnetic force is created. Since the wire loop is stationary the magnetic force acts on the permanent magnet assembly causing its weight to either increase or decrease depending on the direction of the current and the orientation of the magnetic field. The change in the balance reading is due to the magnetic force given by the equation that will be expanded upon later.
- The balance reading is then to be recorded at 0.5 intervals of current (this is altered using the variable resistor)
- One gram is equivalent to a weight of 0.0098 N (0.01 N will probably be accurate enough for this experiment).
Control of Variables
In this experiment it is important to keep variables controlled in order to make this a fair test. There are three variables to consider in this experiment and they are as follows:
1. The length of wire may be varied by exchanging one wire loop for another.
2. The current amplitude may be varied by adjusting the output from the power supply. (The direction of the current flow may also be altered.)
3. The strength of the magnetic field may be altered by varying the number of horseshoe magnets in the magnet assembly. (The direction of the magnetic field may also be altered.)
In this current experiment it is the current that is being investigated and therefore that is the independent variable that will allow us to get different balance readings (dependent variable.) It is important to keep therefore, the length of the wire and the strength of the magnetic field constant. To ensure this I have ensured that there are only two magnadur magnets and that the wire is a set length of 1 metre. It is also important for the wire to have a uniform cross-sectional area, as this increases the surface area of the wire and thus means that the accuracy of the answer will change accordingly
Precautions for accuracy
All school experiments and in fact all experiments conducted by people are all vulnerable to human error and this must be accounted for in order to gain as accurate result as is possible.
In this experiment in order to do this the following was done:
- the temperature of the room was kept note of at all times as to any unusual changes that may effect the experiment, this did not prove to be an issue.
- All balance readings were taken into consideration as +/- 0.01g
- Two readings were taken each time and an average conducted for further accuracy
- The power supply was turned off after each reading to ensure that the wire could return to room temperature after having current passed through it to ensure a more accurate reading.
-
Precautions for safety
1. Caution! A rheostat has been added into the circuit for safety precautions to ensure the current does not get too hot and thus the rod too hot.
2. The power supply should be set to constant current mode. To do so, turn the DC VOLTAGE ADJUST knob fully clockwise, then adjust the DC CURRENT ADJUST knob to obtain the desired output current.
Range and number of readings.
Using an ammeter of range 0 –5 ampere two readings at each 0.5 interval was taken to give a total of 18 readings.
As with all physics laboratory experiments, one must be careful to use the appropriate units. If all forces (i.e., the magnetic force and weight) are measured in Newtons ( ), charges in coulombs ( ), and velocities in meters per second ( ), then as we will see in the explanation the unit of the magnetic field is given as Newton per coulomb-meter per second. In SI units this is known as the tesla ( ).
i have done some results but need help with the graph, conclusion and evaluation just need some guidance could i possibly email my investigation to someone and ask for their hlep? thank you