Page 137 - Physics Form 5 KSSM_Neat

The Power and Energy Consumption Rate for Various Electrical Devices CHAPTER 3

Nowadays, a variety of electrical appliances are available Info GALLERY Electricity
in the market. Consumers need to be wise in choosing
electrical appliances that provide maximum energy saving. The cost of electricity
consumption depends on the
For example, a 40 W Compact Fluorescent Lamp (CFL) amount of electrical energy used
and a 12 W Light Emitting Diode (LED) both produce the in a certain duration (usually 30
KEMENTERIAN PENDIDIKAN MALAYSIA
same brightness. If they are switched on for 12 hours a day, days). The total electrical energy
compare the costs of energy consumption for both lamps for used is measured in kWh.
30 days. 1 kWh = 1 unit of electricity

Table 3.15 Comparison of costs of energy consumption between CFL and LED

CFL LED

Energy used, Energy used,
E = Pt E = Pt
= 0.04 kW × 12 h = 0.012 kW × 12 h
= 0.48 units = 0.144 units
Given that the cost of energy Given that the cost of energy
consumption is RM0.218 per unit; consumption is RM0.218 per unit;
Cost of energy consumption Cost of energy consumption
= 30 days × 0.48 units × RM0.218 = 30 days × 0.144 units × RM0.218
= RM3.139 = RM0.942

The energy consumption of LED is lower than CFL. This shows that LED has a higher
efficiency and is more energy-saving compared to CFL.

Activity 3.10 ISS

Aim: To calculate electrical energy consumption at home
SCAN ME
SCAN ME
Instructions:
Worksheet
1. Carry out this activity individually. (Table 3.16)
2. Scan the QR code and print Table 3.16.
3. List all the electrical appliances that are found in your home https://bit.ly/3hxmyF3
such as electric rice cooker, television, lamp, electric oven, fan,
air conditioner and so on in the table.
4. Collect information on the consumption of electrical energy based on the power rating of the
electrical appliances. For each electrical appliances:
(a) determine the quantity, power and hours used in a day
(b) estimate the cost of electrical energy consumption in your home for a month

LS 3.4.4 127