Mechanical advantage of a machine is defined as :

1. Load x Effort
2. $\dfrac{\text {Load}}{\text {Effort}}$
3. Load + Effort
4. $\dfrac{\text {Effort}}{\text {Load}}$

The mechanical advantage of a lever is equal to :

1. $\dfrac{\text {Load Arm}}{\text {Effort Arm}}\\[0.5 em]$
2. $\dfrac{\text {Effort Arm}}{\text {Load Arm}}$
3. Load Arm + Effort Arm
4. Load Arm - Effort Arm

Wheel is used with axle because :

1. sliding friction is less than the rolling friction
2. rolling friction is less than the sliding friction
3. they work as the inclined plane
4. they help us to change the direction of force.

Fill in the blanks :

(a) The useful work done by an actual machine is always …………… than the work done on the machine.

(b) In class II levers, the …………… is in between fulcrum and …………… .

(c) The mechanical advantage of class …………… lever is always less than 1.

(d) A pulley is used to change …………… .

(e) Mechanical advantage of an inclined plane is always …………… .