Chapter 17 - Current Electricity Flashcards
Definition electric current, I,
Rate of flow of electric charge
S.I Unit for current
Ampere (A)
What is the instrument used to measure current?
Ammeter
Common Circuit Symbols, in notes
okay
What is conventional current?
a flow of the positive charges from the positive terminal of the battery to the negative
When will electric current flow?
Whenever there is a potential difference
Current = ? (Time and Charge)
Charge/Time
What is the Symbol for Charge
Q
Definition of Potential Difference
The work done to drive a unit charge through the two points
What is Symbol Potential Difference
V
Potential Difference = ? (Work done and Charge)
Work Done (or Energy) / Charge
S,I Unit Potential Difference
V
Definition is Electromotive Force
Work don by the cell in driving a unit charge around a complete circuit
Symbol for Electromotive Force
inverted 3
Electromotive Force=?
Work Done/Charge
What is the advantage and disadvantage of the cells in series?
The voltage of each batteries will total up and thus the bulb will be brighter
Cells/batteries will last shorter time
What is the advantage and disadvantage of the cells in parallel?
Cell/Batteries will last longer time
The voltage of each batteries will not total up and only give the voltage of one battery thus the bulb will be less bright just like using the one single cell
Definition of Resistance
the ratio of the potential difference V across it to the current and flowing through it.
Symbol for Resistance
R
S.I.Unit for Resistance
ohms (Ω)
Resistance=?
Voltage/Current
Ohm’s Law state that?
The current passing through a metallic conduction is directly proportional to the potential difference across it, provided that physical conditions (such as temperature) remain constant
A substance that obey Ohm’s Law is called?
Ohmic Conductor
A substance that obey Ohm’s Law is called?
non-ohmic conductor
How is a a graph of V against I for an ohmic conductor looks like?
Linear graph L/
Graph for non-ohmic conductor are curves, pls refers to notes
okay
Symbol for Resistivity
(ρ)
What are the physical properties that will affect resistance?
Temperature
Length
Area
Type of material/Resistivity
When the length of wire increase, its resistance?
Increases
When the Thickness or area of the cross-section of the wire increase, the resistance ?
Decrease
S.I Unit for resistivity
(Ωm)
Resistance = ? (Resistivity, Length, Area)
(ρ) x Length / Area
Good Conductor also have _____ Resistance
Low
Variable resistor is also known as?
rheostat
Variable resistor can adjust resistance of the wire base on which physical property?
Length
Refer to notes for the experiment to determine the resistance of a unknown resistor
okay
