Simple Questions (Paper 4) Flashcards
In a parallel circuit, what is constant?
Voltage (V)
In a series circuit, what is constant?
Current (I)
If you are told to sketch a graph, what are two things you have to draw?
1) Straight line with GRADIENT
2) Labeled Axis and Values
How to tell if circuit is parallel or series?
See if they line up above each other
What is a thermo couple?
Made out of Ammeter , 2 Zinc wires one copper wire, hot junction and a cold junction
What is E.M.F?
Electrical force supplied by the battery in unit time/quantity of charge in a COMPLETE circuit
How to tell if a circuit is working?
Follow the current. The current has to be able to go continuously and reach the battery.
State Ohm’s Law
Voltage (V) is directly proportional to Current (I) at a CONSTANT temperature.
Which makes the Resistance (R) constant.
State R of Thermester
Resistance (R) is inversely proportional to Temperature (Temp)
State the 4 Ferromagnets.
Steel
Iron
Nickle
Cobble
What is the softest Ferromagnet? What is the hardest Ferromagnet?
•Softest is iron
•Hardest is Steel
Why is the core of an electromagnet made of Iron?
Because iron is the softest ferromagnetic material. It magnetises easily, and loses its magnetisation easily.
Define conventional current.
Current moves from Positive ‘+’ Terminal to Negative ‘-‘ terminal.
Where do you place the voltmeter?
Across from the user.
State law of magnetism
Like poles repel, opposite poles attract.
Law of static electricity.
Like charges repel, Opposite charges attract.
What is a neutral point?
When two magnets/charges of Like poles are close together so they repel. That point is without Any forces of attraction.
How to make a magnet?
1) Induction (It re arranges domains)
2) Stroking with an iron rod (it re arranges domains)
3) Electricity. Connect to a DC motor, and move it through a coil slowly. (It re arranges domains)
How to demagnetise a magnet? And why?
1) Hammering/Dropping (It scatters the domains)
2) Heating (Molecules Vibrate faster, so they scatter the domains)
3) Electricity, AC motor. (Scatters domains)
How to strengthen an Electromagnet?
1) Increase current in coil
2) Increase length of wire/coil
3) Increase number of turns in the coil
4) Bring magnets closer
How to know if a wire has the least resistance?
•Smallest Length
•Most thick
•Largest Diameter
