WAEC Past Questions and Answers - Page 3458

17,287.

A relative density bottle of volume 50cm3 is completely filled with a liquid at 30oC. It is then heated to 80oC such that 0.75cm3 of the liquid is expelled. Calculate the apparent cubic expansivity of the liquid.

A.

0.00030k-1

B.

0.00032k-1

C.

0.01970k-1

D.

0.02030k-1

Correct answer is A

Ya = \(\frac{\text{Vol. expelled}}{\text{Vol. left x temp. change}} = \frac{0.75}{49.25 \times 50}\)

= 0.00030k-1

17,288.

A cube made of metal of linear expansivity \(\alpha\) is heated through a temperature \(\theta\). If the initial volume of the cube is Vo, the correct expression for the increase in volume of the cube is

A.

\(\frac{1}{3} \alpha V_o \theta\)

B.

\(\frac{1}{2} \alpha V_o \theta\)

C.

\(2 \alpha V_o \theta\)

D.

\(3 \alpha V_o \theta\)

Correct answer is D

No explanation has been provided for this answer.

17,289.

The gradual cumulative, adaptive and heritable changes in an organism over a long period of time resulting in new species is called

A.

adaptation

B.

survival

C.

organic evolution

D.

interspecific competition

Correct answer is C

No explanation has been provided for this answer.

17,290.

Which of the following is NOT characteristic of social insects?

A.

All members are identical

B.

There is division of labour

C.

The members dwell in the same habitat

D.

Some members protect the queen

Correct answer is A

No explanation has been provided for this answer.