JAMB Physics Past Questions & Answers - Page 113

561.

A man standing 510m away from a wall sounds a whistle. The echo from the wall reaches him 3s later. Calculate the velocity of sound in air.

A.

170 ms-1

B.

340 ms-1

C.

680 ms-1

D.

765 ms-1

E.

1530 ms-1

Correct answer is B

No explanation has been provided for this answer.

562.

An astronomical telescope which is being used to view a very distant object is said to be in normal adjustment if

A.

the final image is at the near-point

B.

the image formed by the objective is before the focus of the eye piece

C.

the angular magnification is the ratio of the focal length of the eye-piece lens to that of the objective

D.

the foci dl the objective and the eye-piece coincide between the lenses

E.

the distance between the objective lens and the eye-piece is equal to the difference between their focal lengths.

Correct answer is D

No explanation has been provided for this answer.

563.

Two 2.0Ω resistors can be combined circuit to give an overall resistance of

A.

0.5Ω only

B.

1.0 Ω only

C.

either 0,5Ω or 1.0 Ω

D.

either 1.0Ω or 4.0 Ω

E.

either 0.5Ω, 1.0Ω or 4.0Ω

Correct answer is D

No explanation has been provided for this answer.

564.

Calculate the peak voltage of a mains supply of r.ms. value 220V.

A.

121 V

B.

156 V

C.

225 V

D.

240 V

E.

311 V

Correct answer is E

No explanation has been provided for this answer.

565.

If the first position of resonance in a resonance tube is 18.0cm from the open end, the distance from the open end to the next position of resonance will be

A.

24.0cm

B.

27.0cm

C.

36.0cm

D.

45.0cm

E.

54.0cm

Correct answer is E

No explanation has been provided for this answer.