WAEC Past Questions and Answers - Page 4082

20,406.

The structure of the embryo which develops and makes contact with the uterine wall is known as the

A.

umbilical cord

B.

placenta

C.

allantois

D.

amnion

E.

chorion

Correct answer is A

No explanation has been provided for this answer.

20,407.

Magnetic flux density is defined as the

A.

total number of magnetic lines of force surrounding a magnet

B.

number of magnetic lines of force per unit area normal to the magnetic field

C.

strength of the magnetic field surrounding a current-carrying conductor

D.

magnetic force exerted on a unit magnetic pole

Correct answer is B

No explanation has been provided for this answer.

20,408.

A resistance wire of length 2 m and of uniform cross-sectional area 5.0 x 10-7 m2 has a resistance of 2.2 Ω Calculate its resistivity

A.

1.8 x 10-7Ωm

B.

5.5 x 10-7Ωm

C.

1.8 x 10-7Ωm

D.

5.8 x 107Ωm

Correct answer is B

No explanation has been provided for this answer.

20,409.

Solve the simultaneous equations y = 3x; 4y - 5x =14

A.

-2,-6

B.

2,6

C.

2,-6

D.

-2,6

E.

-1,-3

Correct answer is B

y = 3x  ... (i);

4y - 5x =14  ... (ii)

Put 3x for y in (ii).

4(3x) - 5x = 14

12x - 5x = 14

7x = 14 ⟹⟹ x = 2.

y = 3x = 3(2) = 6

(x, y) = (2, 6)

20,410.

The parts of a bar magnet at which the magnetic effect is strongest are called the

A.

poles

B.

neutral points

C.

magnetic declinations

D.

magnetic meridians

Correct answer is A

No explanation has been provided for this answer.