WAEC Past Questions and Answers - Page 3276

16,376.

The thermopile is a device for detecting

A.

radioactive radiations

B.

radiant energy

C.

x-rays

D.

the presence of electrons

Correct answer is B

No explanation has been provided for this answer.

16,377.

A metal sheet of area 100cm\(^2\) was heated through 70°C. Calculate its new area if the linear expansivity of the metal is 0.000017K\(^{-1}\).

A.

100.06 cm2

B.

100.12cm2

C.

100.24cm2

D.

100.36cm2

Correct answer is C

Formula: A\(_2\) = A\(_1\)(1 + \(\beta \theta\))

where \(\beta\) = The area expansivity

\(\theta\) = Change in temperature.

\(\beta\) = 2\(\alpha\)

where \(\alpha\) = linear expansivity of the body.

⇒ \(\beta\) = 2 x 0.000017 

= 0.000034 K\(^{-1}\)

\(\therefore\) A\(_2\) = 100 (1 + (0.000034 x 70))

= 100(1 + 0.00238)

= 100(1.00238)

= 100.238 cm\(^2\)

= 100.24 cm\(^2\) (to 2 d.p)

16,378.

Which of the following is a function of a retailer?

A.

Banking services

B.

Hoarding services

C.

Storage services

D.

Sales services

Correct answer is D

After sales service refers to all the things you do for the care and feeding of your valued customers after they buy from you. A retailer purchases in bulk from the wholesalers and sells the products to the customers in small quantities, they provide after sales services such as installation, repairs, helping the customer in transporting the goods bought.

16,379.

The type of monopoly that develops as a result of granting patent right is known as

A.

Natural monopoly

B.

State monopoly

C.

Legal monopoly

D.

Discriminating monopoly

Correct answer is C

A legal monopoly, also known as a statutory monopoly, is a firm that is protected by law from competitors. Patent rights are exclusive right conferred by a patent. This means only the company with the patent can make or produce the product.

16,380.

The factor of production which takes the initiative in combining resources for production is known as

A.

Capital

B.

Land

C.

Entrepreneur

D.

Labour

Correct answer is C

An entrepreneur is a person who combines the other factors of production - land, labor, and capital - to earn a profit.