NECO Physics Past Questions & Answers - Page 13

61.

A ball of mass 100g falls from a height of 5m onto a concrete floor and rebounds to a height of 3m. Calculate the energy lost. (g = 10ms-2)

A.

2J

B.

20J

C.

100J

D.

1000J

E.

2000J

Correct answer is A

No explanation has been provided for this answer.

62.

In which of the following fields is repulsion NOT experienced?

A.

Electrical only

B.

Gravitational only

C.

Magnetic only

D.

Magnetic and electrical

E.

Magnetic and gravitational

Correct answer is B

No explanation has been provided for this answer.

63.

Which of the following statements about the pressure in a liquid is NOT correct? It

A.

acts in all direction

B.

changes with the material of the container

C.

is the same at all points in the same horizontal plane

D.

varies with the density of the liquid

E.

varies with the depth of the liquid

Correct answer is B

No explanation has been provided for this answer.

64.

Determine the value of x from the nuclear reaction below,

\(^{222}_{86}Rn\) → \(^{x}_{88}Ra\) + 2β + energy

A.

220

B.

222

C.

224

D.

226

E.

228

Correct answer is B

The equation above is Beta-decay:
where β is an electron → \(^{0} _{-1}e\)

2β in the equation = \(^{0} _{-1}e\) + \(^{0} _{-1}e\) →  \(^{0} _{-2}e\)

\(^{222}_{86}Rn\) → \(^{x}_{88}Ra\) + \(^{0} _{-2}e\) + energy

where  \(^{x}_{88}Ra\) + \(^{0} _{-2}e\) → \(^{222}_{86}Rn\)

: x = 222 for element Radon [ \(^{222}_{88}Ra\)

65.

Which of the following substances undergoes sublimation?

A.

Ether

B.

Ice

C.

Iodine

D.

Naphthalene

E.

Turpentine

Correct answer is C

No explanation has been provided for this answer.