Explanation:
Watts are defined as 1 Watt = 1 Joule per second (1W = 1 J/s)
which means that 1 kW = 1000 J/s. A Watt is the amount of energy (in Joules) that an electrical device (such as a light) is burning per second that it's running.
Answer:
The net Electric field at the mid point is 289.19 N/C
Given:
Q = + 71 nC = 
Q' = + 42 nC = 
Separation distance, d = 1.9 m
Solution:
To find the magnitude of electric field at the mid point,
Electric field at the mid-point due to charge Q is given by:



Now,
Electric field at the mid-point due to charge Q' is given by:



Now,
The net Electric field is given by:


To do this we may use things that are good conductors - are painted dull black -
Have a air flow around them Maximised.
battery
Explanation:
Electromagnets can be created by wrapping a wire around an iron nail and running current through the wire. The electric field in the wire coil creates a magnetic field around the nail. In some cases, the nail will remain magnetised even when removed from within the wire coil