Simple Machines — Physics STD 10 — Question

Two sounds A and B are of same amplitude, same wave forms but of frequencies f and 2f respectively. Then:

• B differs in quality from A

• B is grave, A is shrill

• B is shrill, A is grave

• B is louder than A

The power of a lens is +2.0 D. Find its focal length and state what kind of lens it is.

Draw a diagram to show the convergent action of a convex lens by treating it as a combination of glass block and two triangular glass prisms, with the aid of two parallel incident rays.

How is the mechanical advantage related with the velocity ratio for an actual machine? State whether the efficiency of such a machine is equal to 1, less than 1 or more than 1.

How is work done by a force measured when the force is in the direction of displacement?

Give scientific reason for the following:
Passengers in a bus are pushed backward when it starts suddenly.

What type of lever is formed by the human body while raising the weight of body on toes?

(a) Give one example of resonance.
(b) What are acoustically measurable quantities related to pitch and loudness?

Out of the two lenses one concave and the other convex state which is a convergent or a divergent type of a lens. Give a reason for your answer.