**Inclined Plane Viva Questions with Answers**

1. What do you understand by an inclined plane?

Ans: It is a smooth plane hinged to the base, so that it can be set at any desired angle.

2. Why do you oil the pulley and the axle of the roller?

Ans: To eliminate friction

3. The roller of weight W is in equilibrium on a smooth inclined plane of angle θ, and the effort ‘P' is required to keep the roller in equilibrium. How are they related

Ans: P = W sinθ

4. What is the shape of the graph and between P and sin θ?

Ans: The graph is a straight line.

5. What is the significance of the slope of the graph?

Ans: The slope of the graph gives the weight of the roller

6. What is the mechanical advantage of the inclined plane?

Ans: It is the ratio of the weight of the roller to the effort. M.A = W/p

7. Define friction.

Friction is an opposing force that comes into play when one body actually moves or even tries to move over the surface of another body.

8. What are the causes of friction?

Interlocking of the elevations and depressions of the surface in contact and the adhesive force between the materials.

9. Name the different types of friction.

(i) Static friction, (ii) Limiting friction, (iii) Sliding friction, (iv) Rolling friction.

10. Define static friction.

Static friction is defined as the opposing force that originates when one body tends to move over the surface of other body, but the real motion has yet not started.

11. Define limiting friction.

Limiting friction is defined as the highest opposing force that originates, when one body is on the verge of moving over the surface of another body.

12. Define sliding friction.

Sliding friction is defined as the opposing force that originates when one body is actually sliding over the surface of another body.

13. What is angle of friction?

It is the angle of inclination of a plane at which a body on it just begins to slide down under gravity.

14. Is rolling friction or sliding friction greater?

Sliding friction is greater than rolling friction.

15. Give the names of some simple machines.

Lever, Pulley, Inclined plane etc

16. What do you understand by an inclined plane?

Inclined plane is one of the simple machines in which a plane surface inclined to the horizontal.

17. Theory of Inclined Plane Experiment?

If P is the force (effort) applied parallel to an inclined plane upwards on a roller of mass m just to keep roller in equilibrium, then,

P = mg sin θ; where mg sin 0 is the component of the gravitational force (ie., the component of the weight W of the roller) acting downwards along the inclined plane. P ∝ sin θ; where sin θ =h/l;l is the length and h the height of the plane.

18. Procedure of Inclined Plane Experiment?

The weight w of the scale pan is found out by a common
balance. The plane is adjusted to a convenient angle θ. The roller is placed on
the plane and the pulley adjusted to make the string parallel to plane. Weight
w_{1} is placed in the pan to make the roller just move up the plane
with a uniform speed. Next, keeping the roller near the top edge of the plane,
the weight w_{2} required in the scale pan to make the roller just to
move down with uniform speed is found out. The mean effort,

P= [(w_{1} + w_{2})/2] + w

The downward force along the inclined plane acting on the roller on account of the gravitational force, i.e., mg sin θ, is equal to the effort P.

P = mg sin θ;

where m = W, is the mass of the roller.

To find sin θ, the length l and the height h of the plane are measured. Then, sin θ is calculated from the equation.

sin θ = (h/l)

The experiment is repeated for different angles of the plane. A graph is drawn with P along the Y-axis and sin θ along the X-axis. The graph is found to be straight line. This shows that P which is equal to the component of the weight of the roller along the plane is directly proportional to the sine of the angle of the inclined plane. The slope of the graph gives the weight of the roller.

The angle θ of the plane is noted from the value of sin θ (Use scientific calculator or logarithm table). A graph is drawn with P and θ. The graph is a curve bent downward. This gives the relation between the components of the weight of the roller along the plane at the angle of the plane.