2020 Physics WAEC (WASSCE) Essay Past Questions (Paper 2)

Question 1

An elastic material of length 3 m is to be stretched to produce an extension three times its original length. Calculate the force required to produce the extension if the force constant of the material is 982.3 Nm^-1

Solution

F = ke

k = 982.3                

e = 3 × 3 m

F = ke

= 982.3 × 3 × 3

∴ F = 8840.7 N

Question 2

In a solar panel for heat supply, state the function of each of the following parts:

(a) Metal flat plate

Answer

To receive and absorb solar radiation to generate heat

(b) Thermal insulator

Answer

To minimize heat loss

(c) Tubes

Answer

To help circulate heat

Question 3

(a) In the design of an optical, what type of material is most suitable for the design of the core?

Answer

i. Glass or plastics or both.

(b) State one condition necessary to confine signals to the core of an optical fibre.

Answer

The refractive index must be greater than that of the cladding.