A plastic comb rubbed with dry hair becomes negatively charged because it does what? A) Gains electrons B) Loses electrons C) Gains protons D) Loses neutrons
A plastic comb becomes negatively charged because it gains electrons from the hair during rubbing, so the correct choice is A) Gains electrons. Protons and neutrons remain bound in the nuclei and do not move between objects in ordinary charging by friction.
What this question is really testing
Charging a comb by rubbing it on dry hair is an example of charging by friction (the triboelectric effect). The key idea is that only electrons transfer between objects in this process.
Why the comb becomes negative
An object is negatively charged when it has an excess of electrons. When the plastic comb is rubbed with hair, electrons move from the hair to the comb, so the comb gains electrons and becomes negatively charged.
Why the other choices are wrong
- B) Loses electrons: Losing electrons would make the comb positively charged, not negative.
- C) Gains protons: Protons are in the nucleus and are not transferred by rubbing.
- D) Loses neutrons: Neutrons are also in the nucleus and do not get transferred in everyday electrostatics.
Quick check
Negative charge means: $$q < 0 \;\Rightarrow\; \text{extra electrons}$$ So the correct option is A.
- Electric Field on the Axis of a Charged Ring
- Quantization of Charge: Meaning and Formula Q = ne
- Dielectric Constant from Capacitor Spacing Change
- Electric Field at 2.0 m From a 4.0 C Charge
- Additional Charge When Inserting a Dielectric (Battery On)
- Electrically Neutral Object: Protons vs Electrons
- Capacitor Voltage from Stored Energy (50.0 mJ)
- Hammer vs Feather in Vacuum: Which Value Differs?
Comments (0)
Please to leave a comment.