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The Right Hand Rule.

Case study : the right hand rule

Use the Right Hand Rule to draw in the directions of the magnetic fields for the following conductorswith the currents flowing in the directions shown by the arrows. The first problem has been completed for you.

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Experiment : magnetic field around a current carrying conductor

Apparatus:

  1. one 9V battery with holder
  2. two hookup wires with alligator clips
  3. compass
  4. stop watch

Method:

  1. Connect your wires to the battery leaving one end of each wire unconnected so that the circuit is not closed.
  2. One student should be in charge of limiting the current flow to 10 seconds. This is to preserve battery life as well as to prevent overheating of the wires and battery contacts.
  3. Place the compass close to the wire.
  4. Close the circuit and observe what happens to the compass.
  5. Reverse the polarity of the battery and close the circuit. Observe what happens to the compass.

Conclusions:

Use your observations to answer the following questions:

  1. Does a current flowing in a wire generate a magnetic field?
  2. Is the magnetic field present when the current is not flowing?
  3. Does the direction of the magnetic field produced by a current in a wire depend on the direction of the current flow?
  4. How does the direction of the current affect the magnetic field?

Case study : magnetic field around a loop of conductor

Consider two loops made from a conducting material, which carry currents (in opposite directions) and are placed in the planeof the page. By using the Right Hand Rule, draw what you think the magnetic field would look like at different points around each of the twoloops. Loop 1 has the current flowing in a counter-clockwise direction, while loop 2 has the current flowing in a clockwisedirection.

If you make a loop of current carrying conductor, then the direction of the magnetic field is obtained by applying the RightHand Rule to different points in the loop.

If we now add another loop with the current in the same direction, then the magnetic field around each loop can be added together to create a stronger magnetic field. A coil of many such loops is called a solenoid . The magnetic field pattern around a solenoid is similar to the magnetic field pattern around the bar magnet that you studied in Grade 10, which had a definite north and south pole.

Magnetic field around a solenoid.

Real-world applications

Electromagnets

An electromagnet is a piece of wire intended to generate a magnetic field with the passage of electric current through it.Though all current-carrying conductors produce magnetic fields, an electromagnet is usually constructed in such a way as to maximizethe strength of the magnetic field it produces for a special purpose. Electromagnets are commonly used in research,industry, medical, and consumer products. An example of a commonly used electromagnet is in security doors, e.g. on shop doors which open automatically.

As an electrically-controllable magnet, electromagnets form part of a wide variety of "electromechanical" devices: machines that produce a mechanical force or motion through electricalpower. Perhaps the most obvious example of such a machine is the electric motor which will be described in detail in Grade 12. Other examples of the use of electromagnets are electric bells, relays, loudspeakers and scrapyard cranes.

Experiment : electromagnets

Aim:

A magnetic field is created when an electric current flows through a wire. A single wire does not produce a strong magnetic field,but a wire coiled around an iron core does. We will investigate this behaviour.

Apparatus:

  1. a battery and holder
  2. a length of wire
  3. a compass
  4. a few nails

Method:

  1. If you have not done the previous experiment in this chapter do it now.
  2. Bend the wire into a series of coils before attaching it to the battery. Observe what happens to the deflection of the needle on the compass. Has the deflection of the compass grown stronger?
  3. Repeat the experiment by changing the number and size of the coils in the wire. Observe what happens to the deflection on the compass.
  4. Coil the wire around an iron nail and then attach the coil to the battery. Observe what happens to the deflection of the compass needle.

Conclusions:

  1. Does the number of coils affect the strength of the magnetic field?
  2. Does the iron nail increase or decrease the strength of the magnetic field?

Magnetic fields

  1. Give evidence for the existence of a magnetic field near a current carrying wire.
  2. Describe how you would use your right hand to determine the direction of a magnetic field around a current carrying conductor.
  3. Use the Right Hand Rule to determine the direction of the magnetic field for the following situations:
  4. Use the Right Hand Rule to find the direction of the magnetic fields at each of the points labelled A - H in the following diagrams.

Questions & Answers

How do hydrogen and chlorine atoms bond covalently in a molecule of hydrogen chloride?
Tiny Reply
what is the parallel circuit
Philani Reply
how many moles of H2O can be formed if 12,5 moi CH4 reacts with sufficient NH3 and O2
Nomcebo Reply
what atoms form covalent bond
hehe Reply
The combination of two non metals
Ndumiso
combined two non-metals 😊
Trudy
what is a mole
Thandeka Reply
a mole is a measure of large quantities of small entities such as atoms, molecules etc
DINEO
what does STP stand for?
Deeco
STP stands for Standard Temperature and Pressure.
Dolly
A car drives straight off the edge of a cliff that is 54m high. The police at the scene of the accident observed that the point of the impact is 130m from the base of the clif. Calculate the initial velocity of the car when it went ovet the clif.
hanyani Reply
wat happens to current if resistors are in parallel connection
Mosima Reply
more current flows from the source that would flow for any of them individually,so the total total resistance is lower
Theoo
In the parallel circuit the current is divided among the resistors
Ndumiso
what are the isotopes
Tlotlisang Reply
are different types of the same elemant but with different mass or atomic no.
Ayanda
i sotopes are different type of element with same atomic number but different mass number
Tareskay
yes i forgot some details😁
Ayanda
next quetion plz
Tareskay
why don't we insert the negative sign for 5 × 10 - 9 when substituting
Mpho Reply
Why does an enclosed gas exert pressure on the walls of a container
Palesa Reply
State the gay lussacs law
Anna Reply
what is the coefficient of Na in order to balanced the equation?_Na + MgCl2=2NaCl+Mg?
Arcel Reply
2
Okuhle
2
Tlotlisang
2
Praise
2
Anna
2
Anelehr
2
Liyema
the combining power of an element, especially as measured by the number of hydrogen atoms it can displace or combine with.
Dealon Reply
Thanks
REJOYCE
download periodic table from play Store...it will explain everything to u
Dealon
what are orbitals
Sphe Reply
examples of atoms whose Valence energy levels are not full and more to bond and become more stable
Sphe
What is a valency
REJOYCE
What a lone pairs...
Ndumiso
Valency is the number of electrons than an atom must gain, lose or share to achieve noble gas configuration.
Mcebisi
what is vacuum
Njabulo Reply
Vacuum, space in which there is no matter or in which the pressure is so low that any particles in the space do not affect any processes being carried on there. It is a condition well below normal atmospheric pressure and is measured in units of pressure (the pascal).
Khayalethu

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Source:  OpenStax, Siyavula textbooks: grade 11 physical science. OpenStax CNX. Jul 29, 2011 Download for free at http://cnx.org/content/col11241/1.2
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