2000 - JAMB Physics Past Questions and Answers - page 2
11
A quantity of water at 0°C is heated to about 30°C. At each degree rise in temperature, its density will
A
rise steadily
B
fall steadily
C
fall then rise
D
rise then fall
correct option: d
Users' Answers & Comments12
I. Coherence
II. Same frequency
III. Same wavelength
IV. Same Intensity
Which of the conditions above are necessary to produce interference fringes?
II. Same frequency
III. Same wavelength
IV. Same Intensity
Which of the conditions above are necessary to produce interference fringes?
A
I and III
B
I, II and IV
C
I, II and III
D
II and III
correct option: c
Users' Answers & Comments13
A boy observes a piece of stone at the bottom of a river 6.0m deep. If he looks from the surface of the river, what is the apparent distance of the stone from him? [Refractive Index of Water = 4/3]
A
8.0m
B
5.5m
C
5.0m
D
4.5m
correct option: d
Refractive Index = Real Depth/App. Depth
4/3 = 6/app. depth
App Depth = (3 x 6)/4 = 4.5m
Users' Answers & Comments4/3 = 6/app. depth
App Depth = (3 x 6)/4 = 4.5m
14
A thin wire with heavy weights attached to both ends is hung over a block of ice resting on two supports. If the wire cuts through the ice block while the block remains solid behind the wire, the process is called
A
condensation
B
sublimation
C
regelation
D
fusion
correct option: c
Users' Answers & Comments15
Dry
Day 1 - 30°C | Day 2 - 29°C | Day 3 - 25°C
Wet
Day 1 - 22°C | Day 2 - 22°C | Day 3 - 21°C
The reading above are for three consecutive days from a wet and dry bulb hygrometer. It can be concluded that the relative humidity for the three days
Day 1 - 30°C | Day 2 - 29°C | Day 3 - 25°C
Wet
Day 1 - 22°C | Day 2 - 22°C | Day 3 - 21°C
The reading above are for three consecutive days from a wet and dry bulb hygrometer. It can be concluded that the relative humidity for the three days
A
decreased steadily
B
remained unchanged
C
increased steadily
D
was least on Day 1
correct option: c
Users' Answers & Comments16
One end of a long wire is fixed while a vibrator is attached to the other end. When the vibrator is energized, the types of waves generated in the wire are
A
stationary and longitudinal
B
stationary and transverse
C
progressive and transverse
D
progressive and longitudinal
correct option: c
Users' Answers & Comments17
A metal of mass 0.5kg is heated to 100°C and then transferred to a well-lagged calorimeter of heat capacity 80JK-1 containing water of heat capacity 420JK-1 at 15°C. If the final steady temperature of the mixture is 25°C, find the specific heat capacity of the metal.
A
877Jkg-1K-1
B
286Jkg-1K-1
C
133Jkg-1K-1
D
92Jkg-1K-1
correct option: c
Let the specific heat cap. of the metal = C
∴ Heat lost by the metal = heat gained by the Calorimeter + Water
∴ 0.5 x C x [100 - 25]
80 x [25 - 15] + 420 [25 - 15]
0.5 x C x 75 = 80 x 10 + 420 x 10
37.5C = 800 + 4200
C = 5000/37.5 = 133.3Jkg-1K-1
Users' Answers & Comments∴ Heat lost by the metal = heat gained by the Calorimeter + Water
∴ 0.5 x C x [100 - 25]
80 x [25 - 15] + 420 [25 - 15]
0.5 x C x 75 = 80 x 10 + 420 x 10
37.5C = 800 + 4200
C = 5000/37.5 = 133.3Jkg-1K-1
18
The main reason for making the cover of a vacuum flask airtight is to prevent heat loss by
A
convection
B
conduction
C
radiation
D
evaporation
correct option: a
Users' Answers & Comments19
A radio is operated by eight cells each of e.m.f. 2.0V connected in series. If two of the cells are wrongly connected, the net e.m.f. of the radio is
A
8V
B
10V
C
12V
D
16V
20
If a charged ion goes through combined electric and magnetic fields, the resultant emergent velocity of the ion is
A
E/B
B
EB
C
B/E
D
E - B
correct option: a
Users' Answers & Comments