ns test

Question 1

what is a force?

Answer 1

a force is a push,pull and twist exerted on an object

Question 2

what is the unit to measure force?

Answer 2

Newton (N)

Question 3

what is contact force?

Answer 3

a force where the two bodies must be touching

Question 4

what is non-contact force?

Answer 4

when two bodies do not have to be touching

Question 5

what is friction?

Answer 5

when 2 objects must be touching and an external force must be applied on the object in an attempt to move it

Question 6

what are three type of friction?

Answer 6

sliding friction,rolling friction and fluid friction

Question 7

what is tension?

Answer 7

tension is a stretching force that pulls on a material

Question 8

what is compression?

Answer 8

compression is a pushing force that squeezes a material

Question 9

what is gravitational force?

Answer 9

when the earth exerts a force of attraction (gravity) on all objects

Question 10

what is magnetic force?

Answer 10

attraction or repulsion that arises between electrically charged particles because of their motion

Question 11

what is static electricity?

Answer 11

an imbalance of electric charges on the surface of an object

Question 12

what is a cell in electric cells?

Answer 12

a cell is something that gives off an electric current as a result of a chemical reaction

Question 13

what is current?

Answer 13

current is the rate of flow of electric charge

Question 14

what is the instrument used to measure current called?

Answer 14

an ammeter (A)

Question 15

what is voltage?

Answer 15

voltage is electrical potential energy and measured in volts

Question 16

what is the instrument used to measure voltage called?

Answer 16

an voltmeter

Question 17

what is a resistor?

Answer 17

to limit the flow of electric current

Question 18

what are series circuits?

Answer 18

any electrically conducting pathway comprising an electric circuit along which the whole current flows through each component.

Question 19

what are parallel circuits?

Answer 19

A parallel circuit has two or more paths for current to flow through

Question 20

what are safety with electricity?

Answer 20

the practice of handling and maintaining electrically powered equipment to prevent incidents

Question 21

what are the use of fuses?

Answer 21

protect electrical circuits from power surges, short circuits, and other issues by breaking the circuit when too much current passes through:

Question 22

what are the use of circuit breakers?

Answer 22

A circuit breaker is an electrical switch designed to protect an electrical circuit from damage caused by overcurrent/overload or short circuit

Question 23

what are earth leakage systems?

Answer 23

An earth-leakage circuit breaker (ELCB) is a safety device used in electrical installations with high Earth impedance to prevent shock.

Question 24

what the use of the three wire in a three-pin
plugs?

Answer 24

brown wire-the live wire
blue wire-the neutral wire
green/yellow-earth wire

Question 25

what are the use of the earth wire?

Answer 25

protects people from electrocution and damage to electrical appliances

Question 26

what is the national grid?

Answer 26

The national electricity grid is a system to deliver electricity around the country

Question 27

what is the cost of electrical power?

Answer 27

Electricity Cost = Electricity Consumption (kWh) x Tariff Rate per unit

Question 28

what is the earth as a system?

Answer 28

The biosphere (life), the lithosphere (land), the hydrosphere (water) and the atmosphere (air)

Question 29

what is the term of lithosphere?

Answer 29

the rigid, outermost layer of the Earth's rocks and minerals, which consists of the crust and upper mantle

Question 30

what is the term of biosphere?

Answer 30

the region of the planet where organisms live

Question 31

what is the term of hydrosphere?

Answer 31

A hydrosphere is the total amount of water on a planet.

Question 32

what is the term of atmosphere?

Answer 32

a layer of gases and suspended solids that surrounds a planet or other celestial body

Question 33

what is the rock cycle?

Answer 33

the processes through which the three main rock types (igneous, metamorphic, and sedimentary) transform from one type into another.

Question 34

what is igneous rock?

Answer 34

they are formed from the cooling and solidification of molten (melted) rock

Question 35

what is sedimentary rocks?

Answer 35

formed from deposits of pre-existing rocks or pieces of once-living organism that accumulate on the Earth's surface

Question 36

what is metamorphic rock?

Answer 36

Rocks that have undergone changes in their physical and chemical properties due to intense heat and pressure deep within the Earth's crust.

Question 37

what is mining of mineral resources?

Answer 37

Mining is the extraction of valuable geological materials and minerals from the surface of the Earth

Question 38

what is extracting ores?

Answer 38

the process of removing valuable metals or minerals from rock that's buried underground, or ore, and treating it to obtain the metal

Question 39

what is surface mining?

Answer 39

Surface mining refers to the removal of the terrain surface to access minerals underneath

Question 40

what is underground mining?

Answer 40

Underground mining is a method of extracting minerals, rocks, and other materials from beneath the earth's surface

Question 41

what is the birth of a star?

Answer 41

stars form from collapsing clouds of gas and dust,initating nuclear fusion that power the star