WAEC Past Questions and Answers - Page 3178

15,886.

An aluminium rod of length 1.8m at 10°C is heated to proceed produce a difference in length of 0.007m. Calculate the temperature to which it is heated. (Linear expansivity of aluminium = 2.3 x 10\(^{-5}\)K\(^{-1}\)

A.

155oC

B.

160oC

C.

169oC

D.

179oC

Correct answer is D

\(\alpha = \frac{L_2 - L_1}{L_1(\theta_2 - \theta_1)}\)

L\(_2\) - L\(_1\) = \(\alpha L_1 (\theta_2 - \theta_1)\)

\(\theta_2 = \frac{0.007}{2.3 \times 10^{-5} \times 1.8}\) + 10

= 179°C

15,887.

Which of the following cannot be classified as land in economics?

A.

Bauxite deposit in the ground

B.

A lake used for irrigation

C.

A bulldozer for clearing farm land

D.

Grazing field for cattle

Correct answer is C

No explanation has been provided for this answer.

15,888.

In a socialist economy, prices of commodities are determined by

A.

Forces of demand and supply

B.

Producers of the commodities

C.

The central planning authority

D.

Consumers who are sovereign

Correct answer is C

No explanation has been provided for this answer.

15,889.

Scale of preference is important for the following reasons except in

A.

Satisfying wants

B.

Making rational

C.

Making optinum allocation of resources

D.

Using scarce resources efficiently

Correct answer is A

No explanation has been provided for this answer.

15,890.

Human wants are insatiable because wants are

A.

Limited while means are scarce

B.

Unlimited and means are also unlimited

C.

Limited and means are also limited

D.

Unlimited while means are scarce

Correct answer is D

No explanation has been provided for this answer.