Explanation:
1. Convex mirror is curved outward.
2. Convex mirror forms an image that is smaller than the object.
3. Concave mirror is used to focus light rays. That's why it is also known as a converging mirror.
4. Plane mirror has a flat surface. It forms the same size of the image as that of the object.
Answer:
Current, I = 1000 A
Explanation:
It is given that,
Length of the copper wire, l = 7300 m
Resistance of copper line, R = 10 ohms
Magnetic field, B = 0.1 T

Resistivity, 
We need to find the current flowing the copper wire. Firstly, we need to find the radius of he power line using physical dimensions as :




r = 0.00199 m
or

The magnetic field on a current carrying wire is given by :



I = 1000 A
So, the current of 1000 A is flowing through the copper wire. Hence, this is the required solution.
Before Copernicus most people were thinking that the Earth is at center of universe. In 1609 Galileo observed sky through his home made telescope.
He found 4 moons orbiting Jupiter..It was a proof that bodies are orbiting other planets and not earth alone. <span>He found the crescent shape of Venus through his telescope and this could happen only if Sun is at center.</span>
Answer:
1500 m/s
Explanation:
Recall that for a wave,
Speed = frequency x wavelength
here we are given frequency = 500 Hz and wavelength = 3m
simply substitute into above equation
Speed = 500 Hz x 3m
= 1500 m/s