JAMB Physics Past Questions & Answers - Page 135

671.

a body is acted upon by forces applied at points P and Q as shown above their resultant is equal to

A.

2√5N in a direction N 56◦ E

B.

2√5N in a direction N 56◦ W

C.

2√13N in a direction N 56◦ E

D.

2√13N in a direction N 56◦ W

E.

√10N in a direction N 56◦ E

Correct answer is C

No explanation has been provided for this answer.

672.

what is the resultant resistance in the circuit given above

A.

11Ω

B.

8Ω

C.

4Ω

D.

3.6Ω

E.

4.3Ω

Correct answer is B

No explanation has been provided for this answer.

673.

what is the resultant capacity of the circuit

A.

1.5µF

B.

18.0µF

C.

6.0µF

D.

6.8µF

E.

8.83µF

Correct answer is A

No explanation has been provided for this answer.

674.

the arrow represents an object in front of a convex mirror whose focal points are X and Y. The image formed is

A.

between X and P

B.

Between P and Y

C.

Between Y and Z

D.

Outside W

E.

Outside Z

Correct answer is B

The image produced by a convex mirror is always virtual, and located behind the mirror.

When the object is far away from the mirror the image is upright and located at the focal point.

675.

The water manometer above is measuring the pressure of gas supply. if the specific gravity of mercury is 13.6 and the atmospheric pressure is 70cm of mercury what is the total pressure of the gas supply in cm of water

A.

67cm

B.

73cm

C.

949cm

D.

952cm

E.

955cm

Correct answer is E

Atmospheric pressure = 70cmHg (which is the height of mecury)
pressure = pgh = pwghw
Where
Pw = density of water
hw = height of water
ph = pwhw
13.6*70 = 1*hw
hw = 952cm

Pressure of gas in cm of water = 952 + 3 = 955cm