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Very Short Question and Answers - What is Power?

Q 1.
What is power?

Ans:

Power is defined as the rate of doing work or the rate of transfer of energy.

Q 2.
Define 1 watt of power.

Ans:

1 watt is the power of an agent that does work at the rate of 1 joule per second.

Q 3.
A lamp consumes 1000 J of electrical energy in 10 s. What is its power?

Ans:

Power = Work/Time = 1000 J / 10 s = 100 W.

Q 4.
Define average power.

Ans:

Average power is obtained by dividing the total energy consumed by the total time taken.

Q 5.
What is the formula for calculating power?

Ans:

Power (P) = Work (W) / Time (t).

Q 6.
Calculate the power expended by Girl A if she climbs a height of 8 m in 20 s carrying a weight of 400 N.

Ans:

Power = (400 N * 8 m) / 20 s = 160 W.

Q 7.
How much power does Girl B expend who takes 50 s to climb the same height?

Ans:

Power = (400 N * 8 m) / 50 s = 64 W.

Q 8.
If a machine does 5000 J of work in 100 s, what's its power?

Ans:

Power = 5000 J / 100 s = 50 W.

Q 9.
What unit is power measured in?

Ans:

The unit of power is watt (W).

Q 10.
How is 1 kilowatt defined in terms of watts?

Ans:

1 kilowatt = 1000 watts.

Q 11.
What physical quantity does a higher power indicate?

Ans:

A higher power indicates that work is done or energy is transferred more quickly.

Q 12.
How many watts are there in 1 kilowatt?

Ans:

There are 1000 watts in 1 kilowatt.

Q 13.
If an agent transfers energy at the rate of 1 J/s, what is its power in watts?

Ans:

Its power would be 1 watt.

Q 14.
If a vehicle is classified based on power, what does a more powerful vehicle indicate?

Ans:

A more powerful vehicle indicates it can do work or transfer energy at a faster rate.

Q 15.
What is the relationship between power, work, and time?

Ans:

Power is directly proportional to the work done and inversely proportional to the time taken.

Q 16.
What does an electric meter measure in your house?

Ans:

An electric meter measures the amount of electric energy consumed over time.

Q 17.
What can you infer if two agents do the same amount of work but in different times?

Ans:

The agent who does the work in less time has more power.

Q 18.
How do you determine average power from your electricity usage?

Ans:

By calculating the total energy consumed and dividing it by the total time taken.

Q 19.
If Girl A performs 3 times the work of Girl B but in half the time, who has more power?

Ans:

Girl A has more power because she completes more work in less time.

Q 20.
In what scenario would one prefer to use kilowatts instead of watts?

Ans:

Kilowatts are preferred when dealing with larger rates of energy transfer, like in household or industrial applications.

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