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Write scientific reason. A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor. - Science and Technology 1

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प्रश्न

Write scientific reason.

A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor.

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उत्तर

  1. The electric heater-cooker works on the principle of heating effect of electric current.
  2. Alloys (such as nichrome) as compared to metals have higher resistivity.
  3. Unlike metals they can be heated to higher temperature.
    Hence, a coil made up of alloy nichrome is used in the electric heater-cooker as a resistor.
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अध्याय 4: Effects of electric current - Write scientific reasons

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एससीईआरटी महाराष्ट्र Science and Technology 1 [English] 10 Standard SSC
अध्याय 4 Effects of electric current
Write scientific reasons | Q 5

संबंधित प्रश्न

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An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Calculate the rate at which heat is developed in the heater.


Name any two effects of electric current.


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Give two reasons why nichrome alloy is used for making the heating elements of electrical appliances.


Why are the coils of electric irons and electric toasters made of an alloy rather than a pure metal?


A resistance of 25 Ω is connected to a 12 V battery. Calculate the heat energy in joules generated per minute.


 How much heat will an instrument of 12 W produce in one minute if it is connected to the heat produced by it?  


The current passing through a room heater has been halved. What will happen to the heat produced by it?


The heat produced in a wire of resistance 'x' when a current 'y' flows through it in time 'z' is given by:

(a) x2 × y × z
(bx × z × y2
(cy × z2 × x
(dy × z × 


An electric iron is connected to the mains power supply of 220 V. When the electric iron is adjusted at 'minimum heating' it consumes a power of 360 W but at 'maximum heating' it takes a power of 840 W. Calculate the current and resistance in each case. 


Give Scientific reason
In the electric equipment producing heat e.g. iron, electric heater, boiler, toaster etc, an alloy such as Nichrome is used, not pure metals.


Identify the figure and give its use.


Solve the following example.

Heat energy is being produced in a resistance in a circuit at the rate of 100 W. The current of 3 A is flowing in the circuit. What must be the value of the resistance?


Answer the following question:
what is the heating effect of the electric current? state any four applications of it?


What is a short circuit?


Write two devices based on the heating effect of electric current.


Explain the importance/uses of fuse wire.


Mark the correct choice

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Reason: The resistance of a conductor depends on length, thickness, nature of material and temperature of the conductor.


An electric kettle consumes 1 kW of electric power when operated at 220 V. A fuse wire of what rating must be used for it?


How does use of a fuse wire protect electrical appliances?


What is Joule’s heating effect? How can it be demonstrated experimentally? List its four applications in daily life.


When a switch is in the OFF position,

(i) circuit starting from the positive terminal of the cell stops at the switch.

(ii) circuit is open.

(iii) no current flows through it.

(iv) current flows after some time. Choose the combination of the correct answers from the following.


What are the factors affecting heating effect of electric current?


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1. Bulb a. Conductor
2. Electroplating b.

Insulator

3. Pure water c.  Heating effect of current
4. Salt solution d. Chemical effect of current

Name a few appliances which work on the basis of the heating effect of current.


The electric fuse works on the Joule heating principle.


Explain why fuse wire is always connected in a series arrangement.


If 220 V potential difference is applied across an electric bulb, a current of 0.45 A flows in the bulb. What must be the power of the bulb?


Tara, after completing her exams, went to her grandmother's house along with her younger brother Rahul. One day, Rahul came home after playing and switched on the fan and air conditioner. At the same time, his grandmother was preparing a milkshake for him using a mixer. Suddenly, they heard a big sound and the electricity of the house got shut down. Tara is called an electrician. He said the main reason for supply to shut down was overloading.

  1. What is overloading?
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  3. How can the effects of overloading be avoided?

Find the odd one out.


When a current I flows through a wire of resistance R for time t then the electrical energy produced is given by ______.


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