NECO Physics Past Questions & Answers - Page 25

121.

Emission spectra are caused by

A.

kinetic energy of moving atoms

B.

potential energy of an electron in an atom

C.

transition of an electron from a higher energy level to a lower energy level

D.

transition of an electron from a lower energy level to higher energy level

E.

transition of excited protons in the nucleus

Correct answer is C

No explanation has been provided for this answer.

122.

A current flows in a series circuit containing a resistor, R, an inductor, L and a capacitor, C. Which of the following is true of the power dissipated in the circuit component(s)?

A.

The power dissipated in L is greater than zero

B.

The power dissipated in R is zero

C.

The sum of the power dissipated in L and C is equal to that in R

D.

The sum of the power dissipated in L and C is greater than in R

E.

The sum of the power dissipated in L and C is zero

Correct answer is E

No explanation has been provided for this answer.

123.

When the same amount of current, I is passed through different wires under the same conditions, the rates of production of heat are

A.

directly proportional to I

B.

directly proportional to the resistances of the wires

C.

directly proportional to the square of the resistances of the wires

D.

inversely proportional to I

E.

inversely proportional to the resistance of the wires

Correct answer is B

No explanation has been provided for this answer.

124.

A car travels with a constant velocity of 45 kmh-1 for 20s. What distance does it cover in this time?

A.

0.025m

B.

0.250m

C.

2.500m

D.

25.000m

E.

250.000m

Correct answer is E

No explanation has been provided for this answer.

125.

Heat

I. is a form of energy
II. is measured with a thermometer
III. cannot be created or destroyed
IV. from a hot object is transferred through conduction only. Which of the statements above are correct?

A.

I and II only

B.

I and III only

C.

I, II and III only

D.

II, III and IV only

E.

I, II, III and IV

Correct answer is B

No explanation has been provided for this answer.