1995 - JAMB Physics Past Questions and Answers - page 2
11
The volume of an air bubble increases from the bottom to the top of a lake at constant temperature because
A
atmospheric pressure acts on the surface of the lake
B
pressure increases with depth
C
density remains constant with pressure
D
the bubble experiences an upthrust
correct option: b
Users' Answers & Comments12
Temperature is the measure of the
A
quantity of heat transferred into the molecules of an object
B
mean kinetic energy of the molecules of the object
C
kinetic energy of any individual molecule of the substance
D
amount of work done by the molecules of the object
correct option: b
Users' Answers & Comments13
A rectangular metal block of volume 10-6m3 at 273k is heated to 573k. If its coefficient of linear expansion is 1.2 x 10-5k-1, the percentage change of it volume is
A
1.5%
B
1.1%
C
0.4%
D
0.1%
correct option: b
Y = \(\frac{\Delta V}{V \times \Delta \theta}\)
3 x 10-5 x 1.2 = \(\frac{\Delta\ V}{10^{-6}\times\ (573 - 273)}\)
\(\Delta\)V = 1080 x 10-11m3
%\(\Delta\)V = \(\frac{1080 \times\ 10}{10^{-6}}\) x 100
= 1.08%
\(\approx\) = 1.1%
Users' Answers & Comments3 x 10-5 x 1.2 = \(\frac{\Delta\ V}{10^{-6}\times\ (573 - 273)}\)
\(\Delta\)V = 1080 x 10-11m3
%\(\Delta\)V = \(\frac{1080 \times\ 10}{10^{-6}}\) x 100
= 1.08%
\(\approx\) = 1.1%
14
A piece of wood floats inside water at room temperature with a fraction of it above the liquid surface. As the temperature of the water is raised, the part of the wood above the liquid will
A
decrease because the density of water decreases with temperature
B
increase because the density of water decreases with temperature
C
decreases because the density of water increases with water temperature
D
increase because the density of water increases with temperature
correct option: a
Users' Answers & Comments15
The equation PxVyTz = constant in charles' law when
A
x = 1, y = -1, z = 1
B
x = 0, y = 1, z = -1
C
x = 1, y = 0, z = -1
D
x = 0, y = 1, z = 1
correct option: b
Users' Answers & Comments16
An electric kettle with negligible heat capacity is rated at 2000W. If 2.0kg of water is put in it, how long will it take the temperature of water to rise from 20OC to 100OC? [specific heat capacity of water = 4200Jkg-1k-1]
A
420S
B
336S
C
168S
D
48S
correct option: b
Heat energy = Elect. energy
mc\(\theta\) = power x time
2 x 4200 x (100 - 20) = 2000 x t
t = 336s
Users' Answers & Commentsmc\(\theta\) = power x time
2 x 4200 x (100 - 20) = 2000 x t
t = 336s
17
A temperature scale has a lower fixed point of 40mm and a upper fixed point of 200mm. What is the reading on this scale when a thermometer reads 60oC?
A
33.3mm
B
36.0mm
C
96.0mm
D
136.0mm
correct option: d
200mm ..... 100oC
Xmm ..... 60oC
400mm ..... 0oC
\(\frac{x - 40}{200 - 40}\) = \(\frac{60 - 0}{100 - 0}\)
X = 136mm
Users' Answers & CommentsXmm ..... 60oC
400mm ..... 0oC
\(\frac{x - 40}{200 - 40}\) = \(\frac{60 - 0}{100 - 0}\)
X = 136mm
18
A quantity of ice at 10oC is heated until the temperature of the heating vessel is 90oC. Which of the following constants is NOT required to determine the quantity of heat supplied to the vessel?
A
specific heat capacity of ice
B
specific heat capacity of water
C
specific latent heat of fusion
D
specific latent heat of vaporization
correct option: d
Users' Answers & Comments19
Which of the following statements give the TRUE difference between evaporation and boiling? i. Evaporation occurs at all temperatures while boiling occurs at a fixed temperature for a given pressure. ii. Evaporation is a surface phenomenon while boiling is an interior phenomenon. iii. Evaporation is affected by surface area while boiling is not.
A
i and ii only
B
i and iii only
C
ii and iii only
D
i, ii, iii.
correct option: d
Users' Answers & Comments20
A well-lagged bar of length 100cm has its ends maintained at 100oC and 40oC respectively. What is the temperature at a point 60cm from the hotter end?
A
58oC
B
62oC
C
64oC
D
76oC
correct option: d
100oC ....100cm
60oC ....60cm
40oC .... 0cm
\(\frac{\theta - 40}{100 - 40}\) = \(\frac{60 - 0}{100 - 0}\)
\(\theta\) = 76oC
Users' Answers & Comments60oC ....60cm
40oC .... 0cm
\(\frac{\theta - 40}{100 - 40}\) = \(\frac{60 - 0}{100 - 0}\)
\(\theta\) = 76oC