The image below shows three kettles with their power ratings and the time they take to boil 500cm3 of water. How many units (kWh) does the 2.2kW kettle use to boil the water? Give your answer to 2 decimal places.

The number of units does the 2.2kW kettle use to boil the water is 0.13 KWh.

Given that,  

here we have to convert 3.5 minutes to hour.  

since

60 mins = 1 hour

Therefore, 3.5 mins =  0.058 hour

Now

So,  

= 2.2 (0.058)

= 0.13 KWh.

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0.13 KWh.

Explanation:

The following data were obtained from the question:

Power = 2.2KW

Time = 3.5 minutes

Next, we convert 3.5 minutes to hour. This is illustrated below:

60 mins = 1 hour

Therefore, 3.5 mins = 3.5/60 = 0.058 hour

Now, we can obtain the energy in KWh as follow:

Power = 2.2KW

Time = 0.058 hour

Energy =?

Power = Energy / time

Cross multiply

Energy = Power x time

Energy = 2.2 x 0.058

Energy = 0.13 KWh.

Therefore, it will take 0.13 KWh for the 2.2KW kettle to boil the water.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

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