Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
RESISTIVITY:
Resistance may be defined as that property of a substance which opposes (or restricts) the flow of current (or electrons) through it. The practical as well as MKS (or SI) unit of ohm (O). 1 ohm is defined as that resistance between two points of a conductor which produces a current of one ampere. When a potential difference of 1 volt is applied to it.
If I is the current flowing through a conductor of resistance R across which a potential difference V is applied then according to ohm's law.
I=V/R
Where V is in volts, R is in the ohms and I is in amperes.
Resistance of a material is:
(a) Directly proportional to its length, l R α l
(b) Inversely proportional to its area of cross section a, Rα1/a
Combining above two facts me have R α l/a
Or R=ρl/A
Where ρ(rho) is a constant depending upon the nature of the material and is known as the specific resistance or resistivity of the material. Putting l=1 and a=1 expression we have R=ρ. Hence resistance of a material of unit length having unit cross-sectional area is defined as the resistivity.
A conductor moves with a velocity of 20m/s at an angle of (a) 90 ? (b) 45 ? (c) 30 ? , to a magnetic field produced among two square-faced poles of side length 2.5cm. If the
for silicon and germinium
What is spontaneous emission? Explain in brief. Spontaneous emission: a. This is the process by that a light source as like an atom, molecule, nano-crystal or nucleus into a
The relative permeability of a paramagnetic substance is (A) Unity. (B) Slightly more than unity. (C) Zero. (D) less than unity. Ans: The relativ
What are different pumping mechanisms in LASERS?
TEMPERATURE: When the conduction electrons are only scattered by thermal vibrations of thermal ions, then τ in the mobility expression refers to the mean time between scatterin
Why should the material used for making permanent magnets have high coercivity? What will be the values of input A and B for the Boolean expression? Why is frequency modulati
After being launched, a rocket attains a speed of 122 m/s before the fuel in the motor is completely used. If you suppose that the acceleration of the rocket is constant at 32.2 m/
Is it possible to see your whole body in a flat, planar mirror that is LESS THAN half your height if the mirror is at an angle? (i.e. not parallel to your body)
Explain about the double-crucible method. Low loss fibers are mostly manufactured by using double crucible and vapour phase deposition method. The double-crucible method is
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd