JAMB Physics Past Questions & Answers - Page 81

401.

Which of the following does NOT describe the Image formed by a plane minor?

A.

Erect

B.

Laterally inverted

C.

Same distance from mirror as object

D.

Magnified

Correct answer is D

The image formed by a plane mirror is always virtual (the light rays do not actually come from the image), upright, and of the same shape and size as the object it is reflecting.

402.

Which of the following is not true of an electrical charge?

A.

Positive charge means deficit electrons

B.

Negative charge means excess of electrons

C.

electric current means movement of electrons

D.

All of the above

Correct answer is D

No explanation has been provided for this answer.

403.

Natural radioactivity consists of the emission of

A.

α- particles and β-rays

B.

α- particles and X-rays

C.

α- particles, β - rays and y-rays

D.

γ- rays and X-rays

Correct answer is C

Radioactivity is the spontaneous emission of radiation from atomic nuclei. This radiation can consist of alpha, beta, and gamma radiation. 

404.

Which of the following is true of an electrical charge?

A.

Positive charge means deficit electrons

B.

Negative charge means excess of electrons

C.

electric current means movement of electrons

D.

All of the above

Correct answer is D

No explanation has been provided for this answer.

405.

The density of 400cm\(^3\) of palm oil was 0.9gcm-3 before frying. If the density of the oil was 0.6gcm-3 after frying, assuming no loss of oil due to spilling, its new volume was?

A.

1360cm\(^3\)

B.

600cm\(^3\)

C.

240cm\(^3\)

D.

8000m\(^3\)

Correct answer is B

\(Density= \frac{mass}{volume}\)

⇒ \(0.9gcm^{-3} = \frac{mass}{400cm^{3}} = 360g\)

without any loss in the frying process, we have

\(0.6gcm^{-3} = \frac{360g}{v}\)

\(v = \frac{360g}{0.6gcm^{-3}} = 600cm^{3}\)