California Cosmetology Written ExamClient Consultation and AnalysisHard
During a strand elasticity test, a cosmetologist stretches a dry strand of hair. Normal, healthy dry hair should be able to stretch approximately what percentage of its original length before returning without breaking?
- A75%
- B20%
- C50%
- D10%
Show answer & explanationAnswer & explanation
Correct answer: B. 20%
Healthy dry hair typically stretches about 20% of its original length and returns without breaking, while healthy wet hair can stretch up to about 50% due to increased elasticity when hydrated. Hair that breaks before reaching these benchmarks indicates low elasticity and possible damage.
Why the other options are wrong
- A. 75% stretch would indicate overly elastic, overprocessed, or damaged hair.
- C. 50% is the benchmark for normal wet hair, not dry hair.
- D. 10% is too low and would indicate diminished, damaged elasticity even for dry hair.
Elasticity Benchmarks (Dry vs. Wet Hair)
Elasticity testing measures how much hair can stretch and return to its original length without breaking; normal dry hair stretches about 20%, while normal wet hair stretches about 50%.
- Dry hair: ~20% stretch is normal
- Wet hair: ~50% stretch is normal
- Breaking before these percentages signals low elasticity/damage
Memory trick: Dry stretches a fifth (20%), wet stretches half (50%) — water adds flexibility.