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प्रश्न
Write two devices based on the heating effect of electric current.
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उत्तर
Fuse wire, electric iron, electric bulb, electric cooker, geyser.
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संबंधित प्रश्न
Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.
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.
How does the resistance of a wire vary with its area of cross-section?
The safety device based on the heating effect of electric current is called a ______.
An electric heater is connected to the 230 V mains supply. A current of 8 A flows through the heater.
(b) How much energy is transferred to the heater each second?
Why does the connecting cord of an electric heater not glow hot while the heating element does?
An electric iron of resistance 20 ohms draws a current of 5 amperes. Calculate the heat produced in 30 seconds.
Explain why, the current that makes the heater element very hot, only slightly warms the connecting wires leading to the heater.
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?
The current passing through a room heater has been halved. What will happen to the heat produced by it?
The elements of electrical heating devices are usually made of:
(a) tungsten
(b) bronze
(c) nichrome
(d) argon
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
(b) x × z × y2
(c) y × z2 × x
(d) y × z × x
Three heaters each rated 250 W, 100 V are connected in parallel to a 100 V supply. Calculate:
- the total current taken from the supply
- the resistance of each heater and
- the energy supplied in kWh to the three heaters in 5 hours.
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.
Answer the following question:
what is the heating effect of the electric current? state any four applications of it?
Write the mathematical expression for Joule’s law of heating.
Compute the heat generated while transferring 96000 coulombs of charge in two hours through a potential difference of 40 V.
In an electric bulb, coil of _______ metal is used.
Which of the following substance contracts on heating?
What is overloading?
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
A current of 1 A is drawn by a filament of an electric bulb. Number of electrons passing through a cross-section of the filament in 16 seconds would be roughly:
Why is parallel arrangement used in domestic wiring?
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.
(a) Observe the diagram given below and state whether the bulb will glow or not when we switch on K.
(b) Is it safe to handle the bulb when the switch is OFF?
(c) Give a reason for your answer in (b).
Name two electric devices for each where
- heating effect of current is used and
- magnetic effect of current is used.
What is an electric fuse made up of?
Name the effect of the current responsible for the glow of the bulb in an electrical circuit.
Define the following:
Electrolyte
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?
In which of the following applications of Iron, rusting will occur most? Support your answer with valid reason.
| A | B | C | D |
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Write an expression for the amount of heat produced in a resistor when an electric current is passed through it stating the meanings of the symbols used.
State the law that explains the heating effect of current with respect to the measurable properties in an electrical circuit.
Anannya responded to the question: Why do electrical appliances with metallic bodies are connected to the mains through a three-pin plug, whereas an electric bulb can be connected with a two-pin plug?
She wrote: Three-pin connections reduce heating of connecting wires.
- Is her answer correct or incorrect? Justify.
- What is the function of a fuse in a domestic circuit?
An electric iron is rated 220 V, 2 kW. If the iron is used for 3h daily find the cost of running it for one week if it costs ₹ 4.25 per kWh.
