Energy pt. 1
Power stations that use wind energy do not contaminate the air.
A. True
B. False
A. True
Coal is a ________ energy source.
A. non- renewable
B. renewable
A. non - renewable
Give the definition of energy efficiency.
The percentage of energy input converted
to useful form of energy output
Which of the following is a renewable energy?
A. geothermal
B. tide
C. radioactive
D. wave
geothermal, tide, wave
Name the type transformer used in sub-station
step - down transformer
Solar cells can produce alternating current.
A. True
B. False
B. False
Biomass, wave and geothermal are all _________ energy sources.
renewable
A transformer has the ability to change the power supply AC 2kW, 240 V to 60 V.
What is the ratio of the number of turn primary to secondary transformer?
4:1
This question is about the electricity transmission and distribution system.
The voltage of the alternating current is _____________ before it is transmitted through the National Grid Network.
A. increased
B. decreased
A. increased
Name the major source of electric supply in Malaysia
water or hydro or hydroelectric
2- pin plugs are not connected to earth wire.
A. True
B. False
A. True
a transformer has the number of turns of the primary and secondary coils as 50 and 250 turns respectively. If the transformer output voltage is 60 V, what is the input voltage?
12 V
Which of the following is the pollutants that gives greenhouse effect
carbon monoxide, nitrogen dioxide, sulphur dioxide
step-up and step-down transformer only work with...
AC / alternating current
This question is about the electricity transmission and distribution system.
The voltage of the alternating current is highest at the ________________.
A. power station
B. national grid network
C. branch substation
B. National grid network
An electric rice cooker rated 800 W, 230 V is switched on for 30 minutes.
Calculate the cost of energy that is used by the rice cooker if the cost per kWh is
30 sen.
12 sen
A microwave oven rated 1.2 kW, 240 V is connected to a 240 V electricity supply.
Calculate the current that flows through the oven.
5A
An electric rice cooker rated 800 W, 230 V is switched on for 30 minutes.
How much electrical energy is used by the rice cooker?
0.4 kWh
The electrical energy used by an air conditioner for 2 minutes is 180 kJ.
Calculate the power of this air conditioner in kilowatts (kW).
1.5
The _____________ enables electricity to be transmitted to the
branch substation when needed.
A. Switch zone
B. National Grid Network
C. power station
A. switch zone
If the number of turns in the primary
coil is 100 and the number of turns in
the secondary coil is 20,
calculate the
secondary voltage if the primary voltage
is 10 V.
2 V
What is the suitable fuse rating of a hair dryer rated 700 W, 240 V?
A. 1A
B. 3A
C. 5A
D. 13A
B. 3A
An electric heater is rated 230 V, 10 A.
Calculate the power of the electric heater in kW.
2.3 kW
An electric heater is rated 230 V, 10 A.
Which fuse is most suitable for the electric heater?
A. 5A
B. 10A
C. 13A
D. 15A
C. 13A
The electrical energy used by an air conditioner for 2 minutes is 180 kJ.
Calculate the power of this air conditioner in watts (W).
1500