Questions
What is a battery? Give full explanation.
A battery is two or more cells that stores energy depending on how big the battery is.
When the cell is connected to a circuit, the __________ terminal of the cell or power supply pushes electrons around in the wires.
When the cell is connected to a circuit, the NEGATIVE terminal of the cell or power supply pushes electrons around in the wires.
How to find voltage with respect to resistance?
voltage = current x resistance
What is resistance?
Resistance is a measure of the opposition to current flow in an electrical circuit
What is current?
Rate or speed that the electrons “flow” or transfer charge past a point throughout a complete circuit
Metals can conduct electricity because they are ________ electrons.
Metals can conduct electricity because they are DECLOCALISED electrons.
Give formula for current with relation to voltage
current = voltage/ resistance
Name four insulators.
Plastic, rubber, paper, wood, pure water, oil, vacuum
Why is electricity a secondary source?
Electricity is a secondary energy source because it is produced by converting primary sources of energy such as fossil fuels, solar energy and wind energy, etc.
An ammeter is used to measure ______ in SI unit of ________.
An ammeter is used to measure CURRENT in S.I unit of AMPERES.
Give current representation.
represented by: I
Why is rubber a better insulator than plastic?
This is because rubber has zero free electrons whereas, plastic has a few comparitively.
Give three uses of switches.
1. Helps to safely break or complete the circuit
2. Controls individual devices
3. Saves energy and money
'Sea of electrons' is also known as DELOCALISED ELECTRONS and are only in METALS.
Give resistance representation and its unit.
R and ohms Ω
Why is silver not used as commonly as copper, even though it is a better conductor of electricity? Give two main reasons/
Although silver is an excellent conductor of electricity, it is not used as commonly due to its high cost. Another reason to avoid using silver is that it rapidly oxidises and tarnishes when exposed to air.
Out of parallel and series circuit, which is most preferred for household? Explain.
1. In parallel circuits, it is possible to control each component separately.
2. The voltage across each lamp is fixed, so the lamp shines with the same brightness, irrespective of how many other lamps are switched on.
The third best conductor of electricity is ________.
The third best conductor of electricity is PURE GOLD.
Draw a parallel circuit diagram on the board, connecting it a cell, two light bulbs, resistor and voltmeter.
(sorry no image possible)
Give two advantages and two disadvantages of series circuit.
ADVANTAGES:
1. It does not overheat quickly.
2. It carries the same current throughout the circuit.
DISADVANTAGES: