NCERT solutions for classes 12 Physics Electrical Resistance Notes
Electrical Resistance 12th Physics: We offer one of the finest 12th Physics courses to our students so that they can easily score good marks in the board exams. Keeping in view the latest pattern of question papers of the CBSE board exams, our faculty has developed the Class 12 Physics notes, sample papers, and NCERT solutions accordingly. Join us today…!
In this article, ‘Electrostatic Resistance’ from Class 12th Physics is being discussed.
What is an Electrical Resistance?
Resistance: The hindrance offered by a conductor to the flow of current.SI unit of resistance is the ohm. The Electrical Resistance of a conductor depends on its length‘l’, cross-sectional area ‘A’, and nature of the material and is given by
R= ?l/A
where ? is the resistivity of the material of the conductor.
Colour code for carbon resistances:
Very high resistances are made of carbon. The value of high resistance is specified by four bands of different colors.
The first three bands represent the value of resistance while the last band represents tolerance. The first band represents the first digit, the second band represents the second digit and the third band represents multiplier in powers of 10. The color of the fourth band tells the tolerance. The absence of the fourth band means tolerance of 20%.
The following table gives the color code:
For practice sets of Current Electricity & more, click on NCERT Physics Class 12.
To memorize the color codes, the following sentence is of great help:
Ques: Determine the resistance of a resistor with the following colors for the rings:
yellow, red, orange, gold.
Ans: We know numbers for yellow, red, orange, gold is 4,2,3 and 5% respectively.
R = 42×103Ω ±5%
Ques: Determine the resistance of the resistor in the following figure:
Ans: Using table,
Resistance R = 47×102Ω ±5%
Ques: How will you represent a resistance 3700 Ω±10% by color code?
Ans: The value of carbon resistance = 3700 Ω±10%
=37×102 Ω±10%
The color attached to numbers 3,7,2 are orange, violet and red respectively.
For 10% accuracy, the color is silver. Thus the bands of color on carbon resistance in the sequence are orange, violet, red, and silver.
Related articles
Conversion of Fahrenheit to Celsius
For more inquires about Physics notes for class 12, regular articles on various topics,12th Science, NCERT solutions class 12, CBSE guide, sample papers, latest updates from CBSE Board, Enroll with Takshila Learning
Follow us on a Social media
Call us: 8800999280/8800999284 or fill the form for any other details:
Tag – Electrical resistance class 12; define electrical resistivity class 12; Colour code of resistance; electrical resistance formula; electrical resistance meaning;
0 responses on "NCERT solutions for classes 12 Physics Electrical Resistance Notes"