JAMB Physics Past Questions & Answers - Page 179

891.

Which of the following is a fundamental quantity?

A.

speed

B.

density

C.

length

D.

impulse

E.

energy

Correct answer is C

No explanation has been provided for this answer.

892.

Find the standard deviation of the following data -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5

A.

2

B.

3

C.

√10

D.

√11

Correct answer is C

x = \(\frac{\sum x}{N}\) = \(\frac{0}{11}\)

= 0

\(\begin{array}{c|c} x & (x - x) & (x - x)^2\\ \hline -5 & -5 & 25 \\ -4 & -4 & 16\\-3 & -3 & 9\\ -2 & -2 & 4\\ -1 & -1 & 1\\ 0 & 0 & 0 \\1 & 1 & 1\\ 2 & 2 & 4 \\ 3 & 3 & 9 \\ 4 & 4 & 16\\ 5 & 5 & 25 \\ \hline & & 110\end{array}\)
S.D = \(\sqrt{\frac{\sum(x - x)^2}{\sum f}}\)

= \(\sqrt{\frac{110}{11}}\)

= \(\sqrt{10}\)

893.
894.

The process whereby a substance changes from a solid to liquid when heat is applied, is called?

A.

Evaporation

B.

Vaporization

C.

Fission

D.

Fusion

Correct answer is D

No explanation has been provided for this answer.

895.

The net charge on the atom is zero because

A.

the electrons and the protons that are charged are in the nucleus

B.

the total charge on the electrons is equal to the total charge on the protons

C.

the neutrons from a shield around the charged protons

D.

the number of electrons in an atom is half the number of protons

E.

A and B above

Correct answer is B

An atom is defined as having the same number of electrons (negative charge), protons (positive charge) and neutrons (no charge). This means that it will have the same amount of negative and positive charge, giving it a net zero charge. On the other hand, an ion has different amount of electrons and protons.