Answer:

Explanation:
At some distance from the Earth the force of attraction due to moon is balanced by the force due to Moon
so we will have

now we have


so we will have

Now by energy conservation



A Magnet is an object that produces a Magnetic Field; it can be formed of a permanent magnet or an electromagnet. The word magnet comes from the Greek "magnítis líthos", which means "Magnesian Stone". Magnesia is an area in Greece (Now Manisa, Turkey) where deposits of magnetite have been discovered since antiquity.
Magnets come in many shapes but no matter what their shapes are, each magnet has a North Pole and a South Pole.
A Magnetic Field is said to exist in a region if a (Magnetic) Force can be exerted on a Magnet. Magnetic Field Lines (Flux Lines) are imaginary lines representing the direction and strength of the Magnetic Field. They go from the North Pole to the South Pole outside the Magnet, and go from the South Pole to the North Pole inside the Magnet. The density of the Magnetic Field Lines is higher near the Poles, and the Magnetic Force is stronger there.
Answer: D
Explanation: Resistance of current in a wire is directly proportional to the length of the wire and inversely proportional to the cross - sectional area of the wire. That is,
R = (rho × L)/A
Where
L = length of the wire
A = cross sectional Area of the wire
rho = resistivity = proportionality constant which depends on the quality of the wire.
Therefore, Resistance and resistivity are related by a:
proportionality constant dependent on the identity of the material.
A becomes positive, while b is now negative. Basically, electrons are negative particles. If they go to somewhere, they make the somewhere they go to negative.
Explanation:
Thomas Edison invented the incandescent light bulb which is kind of like the light bulbs we use today. but they have been improved throughout the years.
hope this is simple and understandable