The notch effect is characterized by which type of cross-sectional change?

• A. A rapid change in cross section
• B. A gradual change in cross section
• C. No change in cross section
• D. An increase in length

Answer: (A)

Notch effect arises when the cross section changes abruptly. That sudden step or notch disrupts how load is carried, causing a localized spike in stress at the change point. If the cross section changes gradually, the transition is smoother and the stress concentration is much lower. A change in length isn’t what defines the notch effect, so it isn’t relevant here. Therefore, the rapid, abrupt change in cross section best describes the notch effect.