WorksheetsThermochemistry, electricity and magnetism
Total questions: 42
Worksheet time: 23mins
In an endothermic reaction the system is absorbing heat energy from surrounding.
True
False
During an endothermic reaction in a beaker if we are part of the surroundings and touched the beaker, it would feel _______.
Warm
Cold
Bubbly
Damp
The diagram shows the reaction of
Endothermic
Exothermic
The following are examples of Exothermic reactions except
Berikut merupakan contoh tindak balas eksotermik kecuali
Combustion/ Pembakaran
Oxidation of metal/ Pengoksidaan logam
Photosynthesis/ Fotosintesis
Respiration/ Respirasi
The following are examples of endothermic reaction except
Berikut merupakan contoh tindak balas endotermik kecuali
Photosynthesis/ fotosintesis
Respiration/ respirasi
reaction between acid and sodium carbonate/ tindak balas acid dengan natrium karbonat
frying eggs/ menggoreng telur
The reaction of calcium chloride and water in the hot pack
tindak balas antara kalsium klorida dengan air dalam pek panas
releases water/ membebaskan air
releases heat/ membebaskan haba
absorbs water/ menyerap air
absorbs heat/ menyerap haba
Cold pack is an example of
pek sejuk merupakan contoh
endothermic reaction/ tindak balas endotermik
exothermic reaction/ tinda balas eksotermik
A student mixed two chemicals to allow them to react. The temperature before the reaction was 25 ° C. The temperature after the reaction was 18° C. Which of the following is true?
It is an exothermic reaction
It is an endothermic reaction
When electricity to an electromagnet is stopped, what happens to the strength of the magnet?
The magnetism stays the same
The magnetism decreases
The magnetism increases
The magnetism stops
The electricity generated from the power plant is
Alternating Current
Direct Current
Delayed Current
Alternating Voltage
How is electricity measured and billed by the power company?
watts
kilowatts
watt hours
kilowatt hours
if a tractor trailer truck is 20% efficient, what happened to the other 80%
energy is destroyed
energy is lost as heat
the 80% is still in the gas tank
energy is converted into matter
which of the following is the least energy efficient light bulbs?
incandescent
compact fluorescent
LED
halogen
You use an LED light bulb that consumes 7 watts that you use for 8 hours in a day. How much would it cost you to run for a month (30 days) if the energy company charges $0.15 per KwHr?
$0.056
$0.0084
$0.25
$2.5
What is the electrical device that changes voltage of an alternating current (A.C.) supply?
transformer
furnace
generator
turbine
Function of the national grid network.
Transmit high voltage alternating current.
Switch off the alternating current.
Step down the voltage of alternating current.
Advantages of National Grid Network.
(More than one answer)
reduce cost, a large quantity of electrical energy can be supplied by two or more power stations.
prevent black out, power station under maintenance can be taken over by another power station.
Transmit low voltage of alternating current to reduce cost.
_______ carries electric current to an electrical appliances.
Neutral wire
Live wire
Earth wire
_______ returns electric current to the branch substation.
Neutral wire
Live wire
Earth wire
___________ disconnects the current supply temporarily when it is not needed (such as during repairing damaged wiring).
ELCB circuit breaker
MCB circuit breaker
Main switch
Electric meter
___________ measures the electrical energy that is used in the house.
ELCB circuit breaker
MCB circuit breaker
Main switch
Electric meter
The main supply of electrical energy in a house has a voltage of
33 kV
415 V
240 V
There are two types of fuse. The wire of _____________ cannot be replaced when melted. A new fuse need to be replaced instead.
Replaceable fuse
Irreplaceable fuse
Cartridge fuse
If an electrical appliance uses current of 11 A, which is the suitable value of fuse to be used.
15 A
5 A
10 A
13 A
Choose the safety components found in wiring system at home.
Lightning conductor
ELCB circuit breker
MCB circuit breaker
Electric meter
Main switch
Why do we increase the voltage to send power around the grid?
To make the grid more efficient by minimizing heat loss
To make it cheaper as we can use thinner wires
To increase the current
The unit for Electrical Power is
hour
ampere
watt
Volt
A toaster, rated 1500 W 240 V, is switched on for 15 minutes. Calculate the energy used.
3600 J
22 500 J
216 000 J
1 350 000 J
An oven rated 750 W, 220 V is switched on for 45 minutes. Calculate the cost of energy that is used by the oven if the cost per 1 unit is 30 sen?
3 sen
17 sen
16875 sen
4 sen
A 5kW electric cooker is used for 55 minutes to cook. Calculate the cost of electrical energy used if the rate per unit is RM 0.50.
RM 7.50
RM 75
RM 1.25
RM 12.50
Choose the CORRECT ways of saving electrical energy usage at home.
Turn off electrical appliances and lights when not in use
Use high power electric lamps and appliances
Ironing only a few pieces of clothing at one time
Avoid opening the refrigerator door regularly
