WAEC Physics Past Questions & Answers - Page 107

531.

A metal rod of density 7000 kgm-3 and cross-sectional area of 0.001257m2 has a mass of 1.76kg. Calculate its length.

A.

0.20m

B.

0.25m

C.

0.40m

D.

0.50m

Correct answer is A

P = \(\frac{M}{AL}\)

L = \(\frac{M}{CA}\)

= \(\frac{1.76}{7000 \times 0.001257}\)

= 0.2m

532.

The density P of a spherical ball of diameter d and mass m is given by

A.

P = \(\frac{3m}{4 \pi d^3}\)

B.

p = 4\(\pi md^3\)

C.

p = \(\frac{6m}{\pi d^3}\)

D.

p = \(\frac{3m}{2 \pi d^3}\)

Correct answer is C

p = \(\frac{M}{V} = \frac{M}{\frac{4}{3} \pi (\frac{d}{\pi})^3}\)

= \(\frac{6m}{\pi d^3}\)

533.

Neutrons are used to induce artificial radioactivity because they

A.

are energetic

B.

have no charge

C.

have no mass

D.

are ionizing

Correct answer is B

No explanation has been provided for this answer.

534.

A nuclide represented as \(^{70}_{32}X\) has a neutron-proton ratio of

A.

0.5

B.

0.8

C.

1.2

D.

1.5

Correct answer is C

\(\frac{38}{32} = 1.2\)

535.

In a cathode ray tube, the function of the x-plates is to

A.

deflect the electron beam horizontally

B.

deflect the electron beam vertically

C.

reflect the electron beam

D.

generate sinusoid waves

Correct answer is A

No explanation has been provided for this answer.