Answer:
b. increasing the number of turns per unit length on the solenoid
e. increasing the current in the solenoid
Explanation:
As we know that energy density depends on the strength of the magnetic field. The magnetic field strength depends on the no of turns of the solenoid and the current passing through it. The greater the number of turns per unit length, greater the current passing through it, more stronger the magnetic field is. As
B = μ₀nI
n = no of turns
I = current through the wire
So the right options are
b. increasing the number of turns per unit length on the solenoid
e. increasing the current in the solenoid
Explanation:
It is given that, a long, straight wire is surrounded by a hollow metal cylinder whose axis coincides with that of the wire.
The charge per unit length of the wire is
and the net charge per unit length is
.
We know that there exist zero electric field inside the metal cylinder.
(a) Using Gauss's law to find the charge per unit length on the inner and outer surfaces of the cylinder. Let
are the charge per unit length on the inner and outer surfaces of the cylinder.
For inner surface,



For outer surface,



(b) Let E is the electric field outside the cylinder, a distance r from the axis. It is given by :


Hence, this is the required solution.
Answer:MOST COMMON METHOD IS USING A LUBRICANT -
A lubricant is a substance, usually organic, introduced to reduce friction between surfaces in ... medical examination. It is mainly used to reduce friction and to contribute to a better and efficient functioning of a mechanism. ... For lubricant base oil use, the vegetable derived materials are preferred
OTHER METHODS-
There are a number of ways to reduce friction:
Make the surfaces smoother. ...
Lubrication is another way to make a surface smoother.
Make the object more streamlined.
Reduce the forces acting on the surfaces.
Reduce the contact between the surfaces.
PLEASE DO MARK ME AS THE BRAINLIEST :)
The answer to the problem b.