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प्रश्न
State four most common electrical appliances based on heating effect of electric current. Why do we use finely heated platinum wire in surgery?
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उत्तर
The four most common appliances based on the heating effect of electrical current are electric iron, electric heater, electric oven and electric toaster. Finely heated platinum wire is used in surgery for cutting tissues much more efficiently than a knife.
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संबंधित प्रश्न
When current is switched ‘on’ in a room heater, it ______.
An electric heater is connected to the 230 V mains supply. A current of 8 A flows through the heater.
(a) How much charge flows around the circuit each second?
Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?
Write down the formula for the heat produced when a current I is passed through a resistor R for time t.
Explain why, tungsten is used for making the filaments of electric bulbs.
A heating coil has a resistance of 200 Ω. At what rate will heat be produced in it when a current of 2.5 A flows through it?
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.
Give a scientific reason:
For electric power transmission, copper or aluminium wire is used.
Identify the figure and give its use.
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?
Solve the following example.
Two tungsten bulbs of wattage 100 W and 60 W power work on 220 V potential difference. If they are connected in parallel, how much current will flow in the main conductor?
Statement 1 : Electric current ( flow of electrons ) creates heat in the resistor.
Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
Explain Statement 1 with the help of Statement 2.
Statement 1 : Electric current ( flow of electrons ) creates heat in the resistor.
Statement 2 : Heat in the resistor is created according to the rule of energy conservation.
Explain Statement 1 with the help of Statement 2.
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.
Compute the heat generated while transferring 96000 coulombs of charge in two hours through a potential difference of 40 V.
The ‘live’ and the ‘neutral’ wires have potential difference of _______.
These days when current in the circuit suddenly increases _______ switches are used.
A coil of an alloy _______ is used in electric heater cooker as a resistor.
Which of the following substance contracts on heating?
What is the heating effect of electric current?
What is a short circuit?
Write two devices based on the heating effect of electric current.
Write scientific reason.
A coil made up of alloy Nichrome is used in the electric heater cooker as a resistor.
Name any two appliances which works on the phenomenon of heating effect of electric current.
Define fuse.
Name some devices that run using heat effect of electric current
Which of the following is correct?
An electric iron consumes energy at the rate of 420 W when heating is at the maximum rate and 180 W when heating is at the minimum rate. The applied voltage is 220 V. What is the current in each case?
How does use of a fuse wire protect electrical appliances?
Three incandescent bulbs of 100 W each are connected in series in an electric circuit. In another circuit another set of three bulbs of the same wattage are connected in parallel to the same source.
- Will the bulb in the two circuits glow with the same brightness? Justify your answer.
- Now let one bulb in both the circuits get fused. Will the rest of the bulbs continue to glow in each circuit? Give reason.
Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness. Both of them connected the wires as shown in the circuit given in the following figure. The current flowing in both the circuits is the same.
- Will the heat produced in both cases be equal? Explain.
- Will the heat produced be the same if the wires taken by them are of equal lengths but of different thickness? Explain.
An electrochemical cell converts ______ energy into ______ energy.
A trip switch is a ______ safety device.
A fuse is used in an electric circuit to stop high currents flowing through the circuit.
Explain why fuse wire is always connected in a series arrangement.
What is the heating effect of electric current?
When a current I flows through a wire of resistance R for time t then the electrical energy produced is given by ______.
