WAEC Past Questions and Answers - Page 3321

16,602.

A metal rod of length 50cm is heated from 40oC to 80oC. If the linear expansivity of the material is \(\alpha\), calculate the increase in length of the rod (in metres) in terms of \(\alpha\)

A.

20\(\alpha\)

B.

200\(\alpha\)

C.

2000\(\alpha\)

D.

20000\(\alpha\)

Correct answer is A

\(L_2 - L_1 = \alpha_1 (\theta_2 - \theta_1) = \alpha \times 0.5 \times 40 = 20 \alpha\)

16,603.

The design of the thermostat of an electric iron is based on the

A.

emmision of electrons from metals when heated

B.

increase in size of metals when heated

C.

increase in the density of metals when heated

D.

change in the mass of metals when heated

Correct answer is B

No explanation has been provided for this answer.

16,604.

Which of the following statements about sex linked traits is not correct?

A.

male inherit sex linked traits from thier fathers

B.

sex linked traits are more common in males

C.

females can be carriers beacuse they can be heterozygous for the trait

D.

males are never carriers since they only recieve one sex chromosome

Correct answer is D

No explanation has been provided for this answer.

16,605.

Which of the following statements best describes a test cross?

A.

to determine the genotype of an individual whose phenotype is to be known

B.

to determine the phenotype of an individual whose genotype is known

C.

between the progeny of parents to ascertain external expressions

D.

between two homozygous recessive individuals to confirm the genotypes

Correct answer is C

No explanation has been provided for this answer.