Given below are two statements, one is labelled as Assertion (A) and the other as Reason (R).

Question

Given below are two statements, one is labelled as Assertion (A) and the other as Reason (R).

Assertion (A): Voices of men and women are different.

Reason (R): Length and thickness of vocal cords is different in men and women.

Select the correct answer from the code given below:

1. A. Both (A) and (R) are true, but (R) is not the correct explanation of (A)
2. B. (A) is false, but (R) is true
3. C. (A) is true, but (R) is false
4. D. Both (A) and (R) are true and (R) is the correct explanation of (A) (Correct answer)

Correct Answer

Option D — Both (A) and (R) are true and (R) is the correct explanation of (A)

Detailed Solution & Explanation

The correct answer is Both (A) and (R) are true and (R) is the correct explanation of (A).

Key Points

• Assertion is true. The voices of men and women differ noticeably in pitch.
• Reason is true. The length and thickness of the vocal cords differ between men and women — roughly 20 mm in men against about 15 mm in women.
• (R) explains (A) exactly: longer, thicker cords vibrate at a lower frequency, producing a deeper voice. Hence option (d).

Additional Information

• Pitch depends on frequency: higher frequency means higher pitch. Typical fundamental frequencies are about 110 Hz for adult men, 220 Hz for adult women and 300 Hz or more for children, whose cords are shortest.
• The deepening of a boy's voice at puberty is caused by the lengthening and thickening of the vocal cords under the influence of testosterone.
• Distinguish the three characteristics of sound:
  • Pitch — determined by frequency
  • Loudness — determined by amplitude, measured in decibels
  • Quality (timbre) — determined by waveform, and the reason two people singing the same note sound different
• The audible range for humans is about 20 Hz to 20,000 Hz; below this is infrasound and above it ultrasound, the latter used in SONAR, medical imaging and echolocation by bats and dolphins.