Answer:
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. A current through the wire creates a magnetic field which is concentrated in the hole, denoting the centre of the coil. The magnetic field disappears when the current is turned off. The wire turns are often wound around a magnetic core made from a ferromagnetic or ferrimagnetic material such as iron; the magnetic core concentrates the magnetic flux and makes a more powerful magnet.
Electromagnets
When an electric current flows in a wire, it creates a magnetic field around the wire. This effect can be used to make an electromagnet. A simple electromagnet comprises a length of wire turned into a coil and connected to a battery or power supply.
Answer:
The charge is 
Explanation:
Given that,
Distance = 2.5 mm
Electric field = 800 NC
Length 
We need to calculate the linear charge density
Using formula of linear charge density


Put the value into the formula


We need to calculate the charge
Using formula of charge

Put the value into the formula


Hence, The charge is 
Answer:
that would be newtons 3rd law
Explanation:
because its how it is
1.7 Btu
1 watt = 3.41214 Btu/h
1watt * 1h = 3.41214 Btu/h * h
1 = 3.41214 Btu/ (watt*h)/
0.5 watt * h = 0.5 watt*h * 3.41214 Btu/(watt*h) = 1.706 Btu
Answer:
no ... hahahha! but I know every boys wait for the day when their heart beat is faster than normal ever in life