CBSE Class 10 Answered
A copper wire ha a diameter of 0.5mm and a resistivity of 
ohm cm. How much of this wire will be necessary to make a 10 ohm coil? How much does the resistance change if the diameter is doubled?
Asked by adalroshan2464 | 28 Mar, 2019, 02:54: PM
Expert Answer
a). As we know resistance of a resistor is define as R = (ρ×l)/A where ρ is resistivity of the material, l is the length of the conductor and A is the cross section area
For given setup
A = π × r^2= 3.14× 0.25×0.25×10^-6 = 1.96 × 10^-7
So putiing all the values we get
10 = (1.6× 10^-8 × l)/1.96 × 10^-7
We get the value of l = 125 m
b). As from the earlier statement we can see that resistance of the wire is inversely proportional to the area of the cross section. So if we increase the radius the resistance will decrease and vice versa
So if the radius is doubled the area becomes 4 times as of its initial value , so the resistance of wire become = 10/4 = 2.5 Ω
Answered by Ankit K | 28 Mar, 2019, 10:19: PM
Application Videos
-
Some other formulae for calculating power ...
This video shows explains the application of formula for calculating the po... -
Cost of electricity
This video describes the calculation of cost of electricity for electrical ... -
Combination of resistors -parallel
This video describes the calculation of effective resistance, total current... -
Combination of resistors -series
This video describes the calculation of electric current flowing through th... -
Current flowing in series combination
This video explains the assertion reason question based on the concept o...
Concept Videos
-
Electricity
Explain a series and a parallel combination of resistors in a circuit. Det... -
Electricity
Explain a series and a parallel combination of resistors in a circuit. Det... -
Electricity
Explain a series and a parallel combination of resistors in a circuit. Det... -
Resistances in series or parallel
This video describes the way to calculate the equivalent resistance for va... -
Resistances in series or parallel
This video describes the way to calculate the equivalent resistance for va...
CBSE 10 - Physics
Asked by kamalaranjanmohantymohanty5 | 06 Jan, 2024, 10:05: AM
ANSWERED BY EXPERTCBSE 10 - Physics
Asked by nandhikasugumar | 05 Oct, 2023, 04:01: PM
ANSWERED BY EXPERTCBSE 10 - Physics
Asked by daniya062008 | 02 Oct, 2023, 08:25: PM
ANSWERED BY EXPERTCBSE 10 - Physics
Asked by prassanna.j | 03 Sep, 2023, 12:28: PM
ANSWERED BY EXPERTCBSE 10 - Physics
Asked by prassanna.j | 03 Sep, 2023, 12:21: PM
ANSWERED BY EXPERTCBSE 10 - Physics
Asked by prassanna.j | 03 Sep, 2023, 12:11: PM
ANSWERED BY EXPERTCBSE 10 - Physics
Asked by prassanna.j | 28 Aug, 2023, 09:49: PM
ANSWERED BY EXPERTCBSE 10 - Physics
Asked by praveenkumae975 | 06 Feb, 2023, 07:19: PM
ANSWERED BY EXPERTCBSE 10 - Physics
Asked by ruparus | 04 Nov, 2022, 09:52: PM
ANSWERED BY EXPERT
