The toughness of a material __________ when it is heated.

Bronze is an alloy of

A. Copper and zinc

B. Copper and tin

C. Copper, tin and zinc

D. None of these

Manganese is added in low carbon steel to

A. Make the steel tougher and harder

B. Raise the yield point

C. Make the steel ductile and of good bending qualities

D. All of the above

The percentage of carbon in low carbon steel is

A. 0.05%

B. 0.15%

C. 0.3%

D. 0.5%

The elastic stress strain behavior of rubber is

A. Linear

B. Nonlinear

C. Plastic

D. No fixed relationship