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Answer: Equal number of protons and electrons. Example: an atom of oxygen atom has 8 electrons and 8 protons and is neutral.
Explanation:
An atom that has no charge is a neutral atom. It contains electrons equal to protons. For example: A neutral atom of oxygen has 8 protons and 8 electrons.
An atom which has charge is said be ionized. It is either positively charged or negatively charged. It is positively charge when the number of electrons is less than the number of protons. For example: contains 10 electrons and 11 protons.
And when the number of electrons is greater than the number of protons, the atom is negatively charged. For example, has 17 protons and 18 electrons. It readily accepts an electron to complete its octet.
Answer:
Explanation:
Motor rating is given in horsepower (hp), it will be converted in watt (W).
Standard to install circuit breaker for an electric circuit is usually 20% ~ 25% more than the Rated Current of the circuit
while
Standard to install overload relay for an electric circuit is usually 20% ~ 25% more than the Running Current of the circuit.
So, to find the maximum capacity of the circuit breaker, rated current of the motor will be multiplied by 1.2 ~ 1.25
Step by Step Explanation:
30hp = 22371W (as 1hp = 745.7)
Assuming unity power factor (cosФ=1) and 208V phase to phase voltage:
Rated Power (watt) = √3 . V.I. cosФ
<em>{if 208V is phase to neutral voltage, then use following formula:</em>
<em> Rated Power (watt) = 3 . V.I. cosФ}</em>
Rated Current = <u>62.169A</u>
So, required maximum rating for circuit breaker is:
20% to 25% of the rated current = 62.17*1.2 ~ 62.17*1.25
=74.6A ~ 77.7A
Hence, any breaker between the above mentioned rating will be appropriate.