Question

If the protons and electrons are the only basic charges in the universe, all the observable charges have to be integral multiples of e. Thus, if an object contains x electrons and y protons, the net charge on the object will be

• A. -(x + y) e
• B. (x + y) e
• C. (x - y) e
• D. (y - x) e

Hint:

Remember that charge is quantized and additive. Always assign a negative sign to the charge of electrons and a positive sign to the charge of protons before summing them up to find the net charge.

Answer 1

The Correct Option is D

Step 1: Concept Definition:
Net charge is the combined algebraic sum of charges of all particles within an object. An electron carries a charge of -e, and a proton carries a charge of +e.

Step 3: Detailed Calculation:
An object comprises 'x' electrons and 'y' protons.
Total charge from 'x' electrons = \( x \times (-e) = -xe \).
Total charge from 'y' protons = \( y \times (+e) = +ye \).
The net charge is calculated as:
\[ \text{Net Charge} = (\text{Total electron charge}) + (\text{Total proton charge}) \]\[ \text{Net Charge} = -xe + ye \]Factoring out 'e' yields:
\[ \text{Net Charge} = (y - x)e \]

Step 4: Conclusion:
The net charge on the object is (y - x)e.