Drift speed of electrons, when $$1.5\,A$$ of current flows in a copper wire of cross section $$5m{m^2},$$ is $$v.$$ If the electron density in copper is $$9 \times {10^{28}}/{m^3}$$ the value of $$v$$ in mm/s close to (Take charge of electron to be = $$1.6 \times {10^{ - 19}}C$$ )
Releted MCQ Question on Electrostatics and Magnetism >> Electric Current
Releted Question 1
The temperature coefficient of resistance of a wire is 0.00125 per $$^ \circ C$$ At $$300\,K,$$ its resistance is $$1\,ohm.$$ This resistance of the wire will be $$2\,ohm$$ at.
The electrostatic field due to a point charge depends on the distance $$r$$ as $$\frac{1}{{{r^2}}}.$$ Indicate which of the following quantities shows same dependence on $$r.$$
A.
Intensity of light from a point source.
B.
Electrostatic potential due to a point charge.
C.
Electrostatic potential at a distance r from the centre of a charged metallic sphere. Given $$r$$ < radius of the sphere.