| 1 | Ferrous Materials | Attracted by magnet and can be magnetized |
Eg. iron, steel, nickel and cobalt |
| 2 | Non-ferrous materials | Not attracted by magnet and cannot be magnetized |
copper, silver, aluminum, wood, glass |
| 3 | Electric field intensity | force exerted by the field on a unit charge placed at a point around another charge | E is the electric field intensity in N/C
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| 4 | Current: Rate of flow of charges in a conductor |
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I is the current in amperes (A), Q is the charge in coulombs (C) t is the time in seconds (s) |
| 5 | Current | In circuits the current always choose the easiest path | |
| 6 | Ohms law | Voltage across the resistor is directly proportional to current, V⋉ I or |
V is the voltage in volts (V), I is the current in amperes (A) and R is resistance in ohms (Ω) |
| 7 | Voltage | Energy per unit charge
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Q is the charge in coulombs (C), V is the voltage in volts (V) Energy is in joules (J) |
| 8 | E.M.F. Electromotive force |
e.m.f. = lost volts + terminal potential difference EMF=Ir+IR |
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| 9 | Resistance and resistivity |
ρ is the resistivity of resistor in Ω.m |
R is the resistance a resistor, L is the length of a resistor in meters A is the area of cross-section of a resistor in |
| 10 | Circuit | In series circuit→ the current stays the same and voltage divides In parallel circuit → the voltage stays the same and current divides |
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| 11 | Resistance in series | ܴ R = R1 + R2 + R3 | R, R1, R2 and R3 are resistances of resistor in ohms |
| 12 | Resistance in parallel | |
R, R1, R2 and R3 are resistances of resistor in ohms |
| 13 | Potential divider | |
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| 14 | Potential divider | |
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| 15 | Power | |
P is the power in watts (W) |
| 16 | Power | |
The unit of energy is joules (J) |
| 17 | Transformer | |
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| 18 | Transformer | Power of primary coil = power of secondary coil
Ip is the current in primary coil and Is the current in secondary coil |
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| 19 | Cathode rays | Stream of electrons emitted from heated metal (cathode). This process is called thermionic emission. | |
