Answer:
a
The magnetic field strength is 
Explanation:
From the question we are told that
The length line above the ground is 
The current of the line is 
The voltage of the line is 
Generally magnetic field strength is mathematically represented as
Where 
is the permeability of free space 
![= (2.0*10^{-7})[\frac{200}{20} ]](https://tex.z-dn.net/?f=%3D%20%282.0%2A10%5E%7B-7%7D%29%5B%5Cfrac%7B200%7D%7B20%7D%20%5D)
Earths magnetic field is approximately given as 
So the percentage would be
%
Answer:
Explanation:
Given
Force 
time interval 
Impulse is given by 
For two significant Figure
Answer:
A velocity of 
Explanation:
Since the magnitude of the vector is equal to the magnitude of velocity, velocity of the 2 cm vector represents a velocity of $10\times 2= 20 \: km/h$.
Answer:
Explanation:
Impulse of a force is measured by force x time or F X t
Impulse also equals change in momentum or
F x t = m v₂ - m v₁
The given case is as follows
in the first case
F x t = mv - o = mv
F = mv / t
in the second case
F₁ x 4 t = mv
F₁ = 1/4 x mv /t
F₁ = F / 4
option a) is correct .
iii )
In the last case
F₂ X t = m v/2 -0
F₂ = 1/2 x mv / t
= 1/2 x F
F₂ = F/2
Option e ) is correct.
Explanation:
The principle of an electric motor is based on the current carrying conductor which produces magnetic field around it. A current carrying conductor is placed perpendicular to the magnetic field so that it experiences a force.
The largest electric motors are used for ship propulsion, pipeline compression and pumped-storage applications with ratings reaching 100 megawatts. Electric motors are found in industrial fans, blowers and pumps, machine tools, household appliances, power tools and disk drives.
