Answer:
When an electric current flows, the shape of the magnetic field is very similar to the field of a bar magnet
Explanation:
Here are the 2 reasons:
- Sun damages the eyes
Long-term, unprotected exposure to ultraviolet light from the sun can damage the retina. The retina is the back of the eye, where the rods and cones make visual images, which are then sent to the visual centers in the brain. Damage from exposure to sunlight can also cause the development of cloudy bumps along the edge of the cornea, which can then grow over the cornea and prevent clear vision. UV light is also a factor in the development of cataracts.
- Heat Exhaustion
According to the Centers for Disease Control and Prevention (CDC), heat exhaustion is the body’s response to excessive loss of water and salt, usually through excessive sweating. People working in a hot environment are at risk of heat exhaustion.
Answer:
finding Cepheid variable and measuring their periods.
Explanation:
This method is called finding Cepheid variable and measuring their periods.
Cepheid variable is actually a type of star that has a radial pulsation having a varying brightness and diameter. This change in brightness is very well defined having a period and amplitude.
A potent clear link between the luminosity and pulsation period of a Cepheid variable developed Cepheids as an important determinants of cosmic criteria for scaling galactic and extra galactic distances. Henrietta Swan Leavitt revealed this robust feature of conventional Cepheid in 1908 after observing thousands of variable stars in the Magellanic Clouds. This in fact turn, by making comparisons its established luminosity to its measured brightness, allows one to evaluate the distance to the star.
