Young's Modulus Compared — Practice Quiz

Question 1

A steel wire (Y = 2 × 10¹¹ Pa) of length 2 m and cross-section 10⁻⁶ m² is loaded with 100 N. Extension:

Accepted Answer

1 mm

Answer

0.1 mm

Answer

10 mm

Answer

0.01 mm

Question 2

If the radius of a wire is doubled, its extension under the same load becomes:

Accepted Answer

1/4 of original

Answer

Same

Answer

Half

Answer

Double

Question 3

Young's modulus has units of:

Accepted Answer

Pa

Answer

N/m

Answer

N·m

Answer

J

Question 4

Energy stored per unit volume in a stretched wire:

Accepted Answer

½·σ·ε

Answer

σ·ε

Answer

Y·ε²

Answer

F·ΔL

Question 5

Two wires, same material, same length but radii r and 2r. The stiffer wire is the one with radius:

Accepted Answer

2r

Answer

r

Answer

Both equally stiff

Answer

Cannot determine