An Ideal Air-Filled Parallel-Plate Capacitor Has Round Plates and Carries

question 31

Multiple Choice

An ideal air-filled parallel-plate capacitor has round plates and carries a fixed amount of equal but opposite charge on its plates.All the geometric parameters of the capacitor (plate diameter and plate separation) are now DOUBLED.If the original energy stored in the capacitor was U₀,how much energy does it now store?

• A) 4U₀
• B) 2U₀
• C) U₀
• D) U₀/2
• E) U₀/4

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Definitions:

Passive Artificial Immunity

Immunity acquired by the transfer of antibodies from another individual, as happens through injection or maternal transfer.

Temporary Immunity

Immunity that is acquired quickly and lasts for a short period, either through the injection of antibodies from another person or animal, or by receiving maternal antibodies through the placenta or breast milk.

Rabies

A viral disease that causes inflammation of the brain in humans and other mammals, transmitted through saliva from bites of infected animals.

Germinal Centers

Specialized sites within lymph nodes and spleen where mature B cells proliferate, differentiate, and mutate their antibody genes during an immune response.