2005 - JAMB Physics Past Questions and Answers - page 3
21
A body of mass 36kg falls through a viscous liquid which offers a drag force of 260N on the body. The upthrust on the body at terminal velocity is?
[g = 10ms2]
[g = 10ms2]
A
100N
B
620N
C
50N
D
310N
correct option: a
For anybody falling through a viscous liquid, at its terminal velocity. the resultant force acting on its is zero. from the equation: Mg - v - u = 0. where v = viscous drag
U = upthrust Mg = weight of the body.
∴ 36 x 10 - 260 - U = 0
∴ U = 360 - 260 = 100N
Upthrust on the body = 100N.
Users' Answers & CommentsU = upthrust Mg = weight of the body.
∴ 36 x 10 - 260 - U = 0
∴ U = 360 - 260 = 100N
Upthrust on the body = 100N.
22
The process whereby the molecules of different substances move randomly is called?
A
capillarity
B
surface tension
C
osmosis
D
diffusion
correct option: d
Users' Answers & Comments23
I. reproducibility
II. Sensibility
III. High terminal capacity
iv. High accuracy
The quantities of a good thermometer include?
II. Sensibility
III. High terminal capacity
iv. High accuracy
The quantities of a good thermometer include?
A
I, II and IV only
B
I, III and IV only
C
I, II and III only
D
II, III and IV only
correct option: d
Users' Answers & Comments24
The process whereby a liquid turns spontaneously into vapour is called?
A
regelation
B
sublimation
C
boiling
D
evaporation
correct option: d
Users' Answers & Comments25
I. Melting
II. Boiling
III. Refraction
IV. Conduction
Which combination of the above is evident of the molecular nature of matter?
II. Boiling
III. Refraction
IV. Conduction
Which combination of the above is evident of the molecular nature of matter?
A
II , III and IV only
B
I ,II and IV only
C
I , III and IV only
D
I , II and III only
correct option: b
Users' Answers & Comments26
When very hot water is poured into two identical thin and thick glass tumblers in equal volumes, the thick one cracks because?
A
of the even expansion of glass
B
glass is a crystal
C
glass is a good conductor of heat
D
of the uneven expansion of gass
correct option: d
Users' Answers & Comments27
Satellite communication network makes use of?
A
visible light
B
sound wave
C
radio wave
D
infra-red wave
correct option: c
Users' Answers & Comments28
An electric device is rated 2000 W, 250 v. The correct fuse rating of the device is?
A
9 A
B
8 A
C
6 A
D
7 A
correct option: b
For the device rated 2000 W, 250 V, implies that current I, flowing is given by the relation
Power = IV
I = (power)/v = (200)/250
= 8A.
∴ the most suitable fuse for the device is 8A
Users' Answers & CommentsPower = IV
I = (power)/v = (200)/250
= 8A.
∴ the most suitable fuse for the device is 8A
29
The north pole of a magnet can never be separated from the south pole because of the property knowledge as?
A
magnetic octopole
B
magnetic monopole
C
magnetic dipole
D
magnetic quadrupole
correct option: c
Users' Answers & Comments30
A car battery rated 45 A H is charged with a charger whose rating is 2.5A.How long will it take to charge the battery full?
A
10 hrs
B
18 hrs
C
20 hrs
D
25 hrs
correct option: b
For a car battery rated 45 AH, being charged by a charger of 2.5 A rating, the time for the battery to be fully charged is given by:
T = (45)/2.5 = 18 hrs
Users' Answers & CommentsT = (45)/2.5 = 18 hrs