Advertisements
Advertisements
प्रश्न
Find the odd one out.
विकल्प
Heater
Toaster
Electric bulb
Electric iron
Advertisements
उत्तर
Electric bulb
Explanation:
Electric bulbs use tungsten filaments, but others have nichrome filaments.
APPEARS IN
संबंधित प्रश्न
Compute the heat generated while transferring 96000 coulomb of charge in one hour through a potential difference of 50 V.
Why is the tungsten used almost exclusively for filament of electric lamps?
Name any two effects of electric current.
An electric room heater draws a current of 2.4 A from the 120 V supply line. What current will this room heater draw when connected to 240 V supply line?
Why are the coils of electric irons and electric toasters made of an alloy rather than a pure metal?
Write down the formula for the heat produced when a current I is passed through a resistor R for time t.
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?
If the current flowing through a fixed resistor is halved, the heat produced in it will become:
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.
Which electric heating device in your home do you think have resistors which control the flow of electricity?
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?
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.
The electricity bill specifies the usage in _______.
Which metal is used to make the filament of an electric bulb?
Name any two appliances which works on the phenomenon of heating effect of electric current.
What does overloading cause?
Explain the heating effect of electric current.
Name any two appliances which work under the principle of heating effect of current.
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.
An electric cell produces electricity from the ______ ______ in it.
Unscramble the following words:
SFEU
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.
What are the uses of electromagnets?
What are the factors affecting heating effect of electric current?
______ wire is used in the filament of the bulbs.
Fuse is a strip of alloy wire which is made up of lead and tin with a very low ______.
The following is not a safety device.
A fuse is used in an electric circuit to stop high currents flowing through the circuit.
The electric fuse works on the Joule heating principle.
Explain why fuse wire is always connected in a series arrangement.
Define the following:
Electrolyte
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.
- What is overloading?
- Is overloading and short the same? When does short-circuiting take place?
- How can the effects of overloading be avoided?
In which of the following applications of Iron, rusting will occur most? Support your answer with valid reason.
| A | B | C | D |
 |
 |
 |
 |
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?
