2. Mobile phones are the most important part of our lives today.
Battery backup is the major concern of the mobile phone users as well as the
mobile phone brands.
Sometimes, we are at place where it is very difficult for us to find a charging point
and we are running out of battery.
Power socket are usually located at places where you cannot keep your phone
properly and there is a chance that your phone may fall down.
Power backup is one of the most important need today.
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3. Power Bank:- The existing solution to this problem is power bank or better known
as the power house. It is a portable device that can charge our mobile phones
using a USB charger. But there is a problem carrying it. Both your hands are
taken in handling the phone and power bank.
Charging Phone Case:- More efficient way of making a power bank is fitting it in
the back cover of the mobile phone. It will be more portable, easy to carry and
more convenient to use.
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8. It is an electric device that is used to heat up water, tea, coffee or any other
beverage.
It takes lesser time than traditional heating devices like gas burner.
It has an element that heats up when electric current passes through it and
provides the required heat energy.
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9. The first kettle to use electricity to heat water came from Carpenter Electric
Company in Chicago in 1891. However, the water took more than 10 minutes to
come to a boil because of a major design problem – the heating element was in a
separate compartment, rather than in the water as is the case in modern kettles.
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10. A base : Which helps in transferring electric energy to the top part.
Heating element : Helps in converting the electric energy to heat energy
Indicator : Helps in indicating if the water has reached the boiling point or not.
Thermostat : Helps in switching off the device when a certain
temperature is reached.
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12. Electric kettle has a thick metal coil in the bottom of container that is called
heating element.
When electricity is allowed to flow the resistance of the heating element turns the
electrical energy into heat energy.
Now when the element is heated then water or any other substance inside it also
start getting heated
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13. 𝑄 = 𝑚𝑐∆𝑇
𝑄
∆t
=
𝑚𝑐∆𝑡
∆t
[Dividing the equation by ∆T ]
𝑃 =
𝑚𝑐∆T
∆t
Also 𝑃 =
𝑉2
𝑅
𝑉2
𝑅
=
𝑚𝑐∆T
∆t
Where Q= Heat energy, m= mass, c=specific heat capacity, ∆T = Change in temperature, ∆t = Time
taken, P= Power used, V= voltage supplied and R= resistance of element.
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14. 1 liter water is heated from 0º C to 100º C in 5 minutes. Calculate the cost of using
the kettle for an hour if rate of electricity is Rs. 5 per unit.
Solution
𝑄 = 𝑚𝑐∆𝑇
𝑄 = 1 × 4182 × 100 or 𝑄 = 418200 𝐽
𝑃 =
𝑄
∆𝑡
𝑃 =
418200
5 ×60
𝑃 = 1394 𝑊 𝑜𝑟 𝑃 = 1.394 𝐾𝑊
𝐴𝑙𝑠𝑜 𝐸 = 1.394 𝐾𝑊ℎ
𝑆𝑜, 𝐶𝑜𝑠𝑡 = 𝐸 × 𝑟𝑎𝑡𝑒
𝐶𝑜𝑠𝑡 = 1.394 × 5 = 𝑅𝑠. 6.97
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15. The original design on holding feels like dropping forward.
So, the innovated design is made conical and the pores have been moved to top of
the beaker and the extra outcome from the side are also removed.
Adding the switch and indicator in the base will reduce the complexity of kettle.
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