What is the length of a nichrome wire of radius 0.32mm, resistance 9.3
ohm and resistivity 15*10^-6 ohm-m? If a potential difference of 10V is applied
across the wire, what will be the current in the wire?
Answers
Answer:
Cells consist of cytoplasm enclosed within a membrane, which contains many biomolecules such as proteins and nucleic acids.[2] Most plant and animal cells are only visible under a light microscope, with dimensions between 1 and 100 micrometres.[3] Electron microscopy gives a much higher resolution showing greatly detailed cell structure. Organisms can be classified as unicellular (consisting of a single cell such as bacteria) or multicellular (including plants and animals).[4] Most unicellular organisms are classed as microorganisms.The cell (from Latin cella, meaning "small room"[1]) is the basic structural, functional, and biological unit of all known organisms. Cells are the smallest units of life, and hence are often referred to as the "building blocks of life". The study of cells is called cell biology, cellular biology, or cytology.
Answer:
The current in the wire is 0.108 Ampere.
Given:
Resistivity of Nichrome=\rho=15 \times 10^{-6} \text{\O}mega m=ρ=15×10−6Ømegam
Potential difference = 10 v
Length = 2m
Radius=0.321 \mathrm{mm}=0.321 \times 10^{-3}=0.321mm=0.321×10−3
Solution:
Area of cross section, A=\pi r^{2}A=πr2
A=\pi\left(0.321 \times 10^{-3}\right)^{2}A=π(0.321×10−3)2
\Rightarrow A=3.24 \times 10^{-7}⇒A=3.24×10−7
On using, the given below resistance formula, we get,
R=\rho \frac{l}{A}R=ρAl
=15 \times 10^{-6}\left(\frac{2}{3.24 \times 10^{-7}}\right)=15×10−6(3.24×10−72)
R=92.6 \text{\O}megaR=92.6Ømega
On using, ohm law, we can get the value of current, as current is a ratio of potential difference and resistance.
I=\frac{V}{R}=\frac{10}{92.6}I=RV=92.610
\Rightarrow I=0.108 A⇒I=0.108A "