$5.$ How does adding damping to a system affect the balancing of a reciprocating engine?

$-$ A$)$ Increases amplitude of vibration at resonance

$-$ B$)$ Reduces the effect of imbalance over a range of speeds

$-$ C$)$ Eliminates the need for balancing masses

$-$ D$)$ Causes an increase in thermal stress

$6.$ What is the effect of secondary imbalance in multi$-$cylinder inline engines?

$-$ A$)$ It causes vertical shaking forces.

$-$ B$)$ It is negligible at all speeds.

$-$ C$)$ It affects the exhaust system efficiency.

$-$ D$)$ It increases fuel efficiency.