Answer:
1.87 A
Explanation:
τ = mean time between collisions for electrons = 2.5 x 10⁻¹⁴ s
d = diameter of copper wire = 2 mm = 2 x 10⁻³ m
Area of cross-section of copper wire is given as
A = (0.25) πd²
A = (0.25) (3.14) (2 x 10⁻³)²
A = 3.14 x 10⁻⁶ m²
E = magnitude of electric field = 0.01 V/m
e = magnitude of charge on electron = 1.6 x 10⁻¹⁹ C
m = mass of electron = 9.1 x 10⁻³¹ kg
n = number density of free electrons in copper = 8.47 x 10²² cm⁻³ = 8.47 x 10²⁸ m⁻³
= magnitude of current
magnitude of current is given as


= 1.87 A
Answer: Urban Green House
Answer:
a)
b)E=0
c)
Explanation:
Given that
A point charge Q is placed at the center of a conducting spherical shell .Due to this - Q charge will induce on the inner sphere surface and +Q will induce on the outer sphere surface .
a) r < a
At a radius r ,from gauss theorem



b) a < r < b

The total induce in this surface = - Q+ Q =0

E = 0
c) r > b



Answer:

Explanation:
Capacitance is defined as the charge divided in voltage.

Introducing a dielectric into a parallel plate capacitor decreases its electric field. Therefore, the voltage decreases, as follows:

Where k is the dielectric constant and
the voltage of the capacitor without a dielectric
The capacitance with a dielectric between the capacitor plates is given by:

Where k is the dielectric constant and
the capacitance of the capacitor without a dielectric. So, we have:

Therefore, a capacitor with a dielectric stores the same charge as one without a dielectric.
Answer:
imma go with either b or A