Physics
Grade-9
Easy
Question
To increase the efficiency of energy use, we could
- Turn off the lights when not in use
- Keep the car running as you go in the store
- Water the plants in a drought
- All of the above
Hint:
Turn off the light when not in use.
The correct answer is: Turn off the lights when not in use
Incandescent lights should be turned off whenever they are not needed, because they are the least efficient type of lighting. 90% of the energy they use is given off as heat, and only about 10% results in light. Turning lights off will also keep a room cooler, an extra benefit in the summer.
Related Questions to study
Physics
Which reading is greater?
Which reading is greater?
PhysicsGrade-9
Physics
A cyclist puts 600 J of work on his bicycle and the bicycle gives out 140 J of useful work. Calculate the energy efficiency of the cyclist.
A cyclist puts 600 J of work on his bicycle and the bicycle gives out 140 J of useful work. Calculate the energy efficiency of the cyclist.
PhysicsGrade-9
Physics
A certain appliance requires 1,755 watts. How much would it cost to run the appliance for a total of 33 minutes at a cost of Rs10 per kWh?
A certain appliance requires 1,755 watts. How much would it cost to run the appliance for a total of 33 minutes at a cost of Rs10 per kWh?
PhysicsGrade-9
Physics
A certain appliance requires 2,141 watts. How much would it cost to run the appliance for a total of 27 minutes at a cost of Rs 12 per kWh?
A certain appliance requires 2,141 watts. How much would it cost to run the appliance for a total of 27 minutes at a cost of Rs 12 per kWh?
PhysicsGrade-9
Physics
The law of conservation of energy states that when one form of energy is converted into another
The law of conservation of energy states that when one form of energy is converted into another
PhysicsGrade-9
Physics
Your monthly electricity bill listed two-meter readings. The previous reading was 1346 kWh and the present reading is 2456 kWh. If the company charges 6Rs/unit, how much was your electric bill for the month?
Your monthly electricity bill listed two-meter readings. The previous reading was 1346 kWh and the present reading is 2456 kWh. If the company charges 6Rs/unit, how much was your electric bill for the month?
PhysicsGrade-9
Physics
What is the reading in the fourth dial “D”?
What is the reading in the fourth dial “D”?
PhysicsGrade-9
Physics
What is the reading in the third dial “c”?
What is the reading in the third dial “c”?
PhysicsGrade-9
Physics
What is the reading in the second dial “b”?
What is the reading in the second dial “b”?
PhysicsGrade-9
Physics
What is the reading in the first dial “A”?
What is the reading in the first dial “A”?
PhysicsGrade-9
Physics
Which number needs to be ignored in a dial meter?
Which number needs to be ignored in a dial meter?
PhysicsGrade-9
Physics
Which is the symbol of the standard unit of electricity supplied to the consumer, which is equal to 1 kilowatt acting for 1 hour?
Which is the symbol of the standard unit of electricity supplied to the consumer, which is equal to 1 kilowatt acting for 1 hour?
PhysicsGrade-9
Physics
Which choice below completes the following statement correctly?
When a sandwich maker is used
Which choice below completes the following statement correctly?
When a sandwich maker is used
PhysicsGrade-9
Physics
Which is cheaper?
Which is cheaper?
PhysicsGrade-9
Physics
What is the efficiency of a CFL?
What is the efficiency of a CFL?
PhysicsGrade-9
