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प्रश्न
How will you infer with the help of an experiment that the same current flows through every part of the circuit containing three resistances in series connected to a battery?
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उत्तर
Take three resistances R1, R2 and R3
- Connect them in series combination using battery, ammeter and key as shown in the diagram.
- First of all, connect the ammeter between battery and R1 and note down the reading.
- After that, connect the ammeter between R1 and R2 and note down the reading.
- After that, connect the ammeter between R3 and battery.
- Note down the reading of the ammeter in each steps.
It is observed that ammeter shows the same reading in all the three situations. This shows that same current flows through all the three resistors.
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संबंधित प्रश्न
List the factors on which the resistance of a conductor in the shape of a wire depends.
Fill in the following blanks with suitable words:
Copper is a good .......... Plastic is an ..........
Which has less electrical resistance : a thin wire or a thick wire (of the same length and same material)?
Name the electrical property of a material whose symbol is "omega".
What happens to the resistance as the conductor is made thicker?
Which has more resistance:
a thick piece of nichrome wire or a thin piece?
What do you understand by the "resistivity" of a substance?
A wire is 1.0 m long, 0.2 mm in diameter and has a resistance of 10 Ω. Calculate the resistivity of its material?
Give two examples of substances which are good conductors of electricity. Why do you think they are good conductors of electricity?
How does the resistance of a conductor depend on:
length of the conductor?
What would be the effect on the resistance of a metal wire of:
increasing its length?
Calculate the area of cross-section of a wire if its length is 1.0 m, its resistance is 23 Ω and the resistivity of the material of the wire is 1.84 × 10−6 Ω m.
The element used almost exclusively for filaments of incandescent lamps:
Assertion: Conductors allow the current to flow through themselves.
Reason: They have free charge carriers.
Use the data in the Table given below to answer the following –
Which material is the best conductor?
Table give below Electrical resistivity of some substances at 20°C
| Electrical resistivity of some substances at 20°C | ||
| − | Material | Resistivity (Ω m) |
| Conductors |
Silver | 1.60 × 10−8 |
| Copper | 1.62 × 10−8 | |
| Aluminium | 2.63 × 10−8 | |
| Tungsten | 5.20 × 10−8 | |
| Nickel | 6.84 × 10−8 | |
| Iron | 10.0 × 10−8 | |
| Chromium | 12.9 × 10−8 | |
| Mercury | 94.0 × 10−8 | |
| Manganese | 1.84 × 10−6 | |
| Alloys |
Constantan (alloy of Cu and Ni) |
49 × 10−6 |
| Manganin (alloy of Cu, Mn and Ni) |
44 × 10−6 | |
| Nichrome (alloy of Ni, Cr, Mn and Fe) |
100 × 10−6 | |
| Insulators | Glass | 1010 − 1014 |
| Hard rubber | 1013 − 1016 | |
| Ebonite | 1015 − 1017 | |
| Diamond | 1012 − 1013 | |
| Paper (dry) | 1012 | |
Plastic insulation surrounds a wire having diameter d and length l as shown above. A decrease in the resistance of the wire would be produced by an increase in the ______.
The resistance of a wire of 0.01 cm radius is 10 Ω. If the resistivity of the wire is 50 × 10-8 Ω, find the length of this wire.
How will the resistance of a wire be affected if its
- length is doubled, and
- radius is also doubled ?
Give justification for your answer.
