Tutor profile: Elijah S.
Subject: Physics (Electricity and Magnetism)
True or false: Electric and Magnetic Dipoles are the fundamental units of electric and magnetic fields, respectively. How does this statement relate to Maxwell's equations?
This statement is false. Magnetic dipoles do not exist in nature. Magnetic mono-poles create magnetic fields in space. This is why Gauss's Law for magnetism (one of Maxwell's 4 equations) states that the magnetic flux across a closed surface is always 0.
Subject: C Programming
What is the difference between a list and array in C? Which is better when items in this structure's item and size are changed frequently?
A list is a linked group of data items, where each data point contains a pointer to the location of the next item in the list. The final data point in the list contains a NULL pointer. A list requires sequential access, meaning the nth item can only be accessed by starting at the beginning and proceeding through the list to the nth item. An array is an ordered group of data items, where each item in the array is numbered. Items in an array can be accessed sequentially, or randomly. A list is better for the proposed application. An array must create copy of each item it contains each time the size is changed and delete each old item.
What is the difference between a movement along the demand curve and a change (or shift) of the demand curve itself? Give an example of each case.
A movement along the demand curve occurs when price or quantity has changed. For example, an increase in price will lower the quantity demanded. This results in a movement "upward" and to the left, as price and demand are inversely related. A shift of the demand curve occurs when the entire curve is moved to the left or to the right. The slope remains the same, while the x and y intercepts have been displaced. For example, if the price of a substitute good increases, the curve will shift to the right. Now, there is more quantity demanded at the same price.
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