printer-friendly sample test questions
... A. Voltage is a measure of the amount of force pushing a current. B. A wire carrying an electric current induces a magnetic field around it. C. Electricity is transmitted over power lines at very high voltages. D. When electrons flow through a material they meet resistance. ...
... A. Voltage is a measure of the amount of force pushing a current. B. A wire carrying an electric current induces a magnetic field around it. C. Electricity is transmitted over power lines at very high voltages. D. When electrons flow through a material they meet resistance. ...
Two ways of looking at a transformer
... magnet (small motors) or by a current-carrying coil as above. The rotating assembly (known as the Armature) is supplied with current via the Commutator and the Brushes which make a sliding contact with the commutator. The purpose of the commutator is to reverse the armature current every half-revolu ...
... magnet (small motors) or by a current-carrying coil as above. The rotating assembly (known as the Armature) is supplied with current via the Commutator and the Brushes which make a sliding contact with the commutator. The purpose of the commutator is to reverse the armature current every half-revolu ...
Magnetism and Electric Currents
... • A solenoid is a long wire wound into many closely spaced loops forming a coil • When current passes through the wound up wire, it produces a strong magnetic field inside of the coil • This is referred to as an electromagnet because the magnetic field only exists when current flows through the wire ...
... • A solenoid is a long wire wound into many closely spaced loops forming a coil • When current passes through the wound up wire, it produces a strong magnetic field inside of the coil • This is referred to as an electromagnet because the magnetic field only exists when current flows through the wire ...
ANSWER SHEET
... Student is obliged to bring with into the testing room and display her/his ID with photo for identification purposes. If there is a discrepancy in a student's identification, the student may be dismissed from the testing room. You may not bring cell phones, MP3 players, pagers, or PDA’s into the tes ...
... Student is obliged to bring with into the testing room and display her/his ID with photo for identification purposes. If there is a discrepancy in a student's identification, the student may be dismissed from the testing room. You may not bring cell phones, MP3 players, pagers, or PDA’s into the tes ...
Bellringer - Madison County Schools
... wire, through a magnetic field. By doing this, you will create an electrical current in the ...
... wire, through a magnetic field. By doing this, you will create an electrical current in the ...
PaperClip Motor
... represents the direction of the current. Your middle finger represents the direction of the magnetic field. Lastly, your thumb represents the direction of the force. ...
... represents the direction of the current. Your middle finger represents the direction of the magnetic field. Lastly, your thumb represents the direction of the force. ...
IGCSE Electricity definitions
... ALTERNATING CURRENT: An electric current which is constantly changing direction of its flow. The mains supply is AC. AMMETER: An instrument which measures electric current. It must be connected in series with the current it is measuring. SERIES: Components connected end to end in a chain. PARALLEL: ...
... ALTERNATING CURRENT: An electric current which is constantly changing direction of its flow. The mains supply is AC. AMMETER: An instrument which measures electric current. It must be connected in series with the current it is measuring. SERIES: Components connected end to end in a chain. PARALLEL: ...
Inductor FAQ`s - RCD Components
... resistance, AC inductor designs focus on impedance because the impedance is dominant over the DC resistance and varies with frequency. Material losses must also be accounted for. Another issue is the skin effect. When RF voltage is used the alternating current causes the current to migrate to the su ...
... resistance, AC inductor designs focus on impedance because the impedance is dominant over the DC resistance and varies with frequency. Material losses must also be accounted for. Another issue is the skin effect. When RF voltage is used the alternating current causes the current to migrate to the su ...
Faraday`s Law of Induction
... It is possible to induce current to flow in a wire as long as there is Warning! a changing magnetic field involved. Many people incorrectly use the ● One way is push a length of wire through a magnetic field, “force” part of the third hand rule as so that the wire is moved perpendicular to the magn ...
... It is possible to induce current to flow in a wire as long as there is Warning! a changing magnetic field involved. Many people incorrectly use the ● One way is push a length of wire through a magnetic field, “force” part of the third hand rule as so that the wire is moved perpendicular to the magn ...
Electromagnetic Rules
... produced if the velocity and the direction of the field are parallel to each other. When the velocity is perpendicular to the magnetic field the EMF will be produced that is perpendicular to both. The directions are determined by the “right hand rule” where the right hand thumb points in the directi ...
... produced if the velocity and the direction of the field are parallel to each other. When the velocity is perpendicular to the magnetic field the EMF will be produced that is perpendicular to both. The directions are determined by the “right hand rule” where the right hand thumb points in the directi ...
Unit 17 – Alternating Current (AC) Circuits Containing Inductance
... voltage is induced in the coil ii) This induced voltage is always in opposition to the applied voltage (counter-electromotive force) iii) The amount of induced voltage is proportional to the rate of change of current iv) An inductor opposes a change of current e) Calculating the induced voltage i) A ...
... voltage is induced in the coil ii) This induced voltage is always in opposition to the applied voltage (counter-electromotive force) iii) The amount of induced voltage is proportional to the rate of change of current iv) An inductor opposes a change of current e) Calculating the induced voltage i) A ...
Quiz on Domestic Electrical Appliances
... 4. Which of the following appliance has the heating element hidden and is separated from the other metallic part of the body? ...
... 4. Which of the following appliance has the heating element hidden and is separated from the other metallic part of the body? ...
Skin effect
Skin effect is the tendency of an alternating electric current (AC) to become distributed within a conductor such that the current density is largest near the surface of the conductor, and decreases with greater depths in the conductor. The electric current flows mainly at the ""skin"" of the conductor, between the outer surface and a level called the skin depth. The skin effect causes the effective resistance of the conductor to increase at higher frequencies where the skin depth is smaller, thus reducing the effective cross-section of the conductor. The skin effect is due to opposing eddy currents induced by the changing magnetic field resulting from the alternating current. At 60 Hz in copper, the skin depth is about 8.5 mm. At high frequencies the skin depth becomes much smaller. Increased AC resistance due to the skin effect can be mitigated by using specially woven litz wire. Because the interior of a large conductor carries so little of the current, tubular conductors such as pipe can be used to save weight and cost.