DC is the acronym of English direct current, which means: direct current, referred to as direct current or direct current.
Current is divided into AC current and DC current.
Alternating current: Electrical appliances plugged in use alternating current.
Direct current: Electrical appliances using external power supply use direct current.
Alternating current is widely used in household circuits, and the voltage is 220V, which is a dangerous voltage.
Direct current (lithium battery) is widely used in mobile phones. Like batteries (1.5V), lithium batteries and storage batteries, they are all called direct current.
Physically, the direction of current is the direction of positive charge directional motion. The direction of current is opposite to that of electrons.
Charge refers to free charge, which is also called free ion in metal conductor. There are positive ions and negative ions in the aqueous solution of acid, alkali and salt.
Outside the power supply, the current flows in the direction where the positive charge moves. Inside the power supply, it flows back from the negative electrode to the positive electrode.
Extended data
André-Marie Ampère 1775 ~ 1836), a French physicist, also contributed to mathematics and chemistry. 1775 65438+1was born in a wealthy family in Lyon on October 22nd. He showed his talent in mathematics when he was young. His father believed in J.J. Rousseau's educational thought and provided him with a large number of books, which made him embark on the road of self-study, so he read widely and absorbed nutrition; Rousseau's works on botany ignited his enthusiasm for science.
When I was a child, Ampere had a strong memory and outstanding mathematical ability. His father was deeply influenced by Rousseau's (17 12- 1778) educational thought, and decided to let Ampere teach himself and often took him to the library to read books. Ampere taught himself the history of science, encyclopedias and other works. He was most fascinated by mathematics, and published his first mathematical paper at the age of 13, discussing the spiral line.
1799 ampere teaches mathematics in a middle school in Lyon. 1802 In February, Ampere left Lyon to teach physics and chemistry at Fort College. In April, he published an article about the mathematical theory of gambling, which revealed the excellent mathematical foundation and attracted the attention of the society. Later, he applied for a position in the French public school founded by Napoleon.
1808, Ampere was a governor of Imperial University of France, 1809, he was a professor of mathematics at the University of Paris. 18 14 was elected as an academician of the French Academy of Sciences. 1824 professor of experimental physics, French college. 1827 was elected as a member of the Royal Society of London. He is also an academician of the Academy of Sciences such as Berlin and Stockholm.
References:
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