QUESTIONS and ANSWERS 2

a)         what must be true about two objects for conduction to take place?

they must have a thermalconct, in terms of conduction of  eat.

b)         which factors affect heat transfer between a warm and a cool substance?

the two substance must a thermal contact for te transfer of heat to occur, this is according to the zero law of thermodynamics, which that , if a body A and another body B are at thermal equilibrium with another body C, then both body A and B are also at thermal equilibrium;
 thermal equilibrium simply means same temperature,
c)         how does radiation help treat cancer?
radiation can treat cancer , when the cancerous cells are exposed to to this radiations, this will destroy the DNA of tis cells and are removed from the body by natural process
d)         how does an increase in thermal energy affect molecules?
 when the thermal energy of a body changes, the kinetic energy of the individual particles of the body increases, this makes the particles to vibrate at greater speed and more violently,  eventually the crystal structure of substance is weaken and the it collapse, and individual particle are now free to translate, ( translation motion) if the substance is in solid it changes to liquid and if in liquid the particles escapes as gases.

e)         hot coffee in a mug cools over time and the mug warms up. which describes the energy in this system?
a)         convention
b)         conduction
c)         radiation
d)         none of the above
f)         which substance has the most thermal energy and will have the most heat flow from it?
a)         1kg of groundnut oil
b)         20g of iron
c)         100og of sugar
d)         1kg of uranium
g)         heat transfer between two substances is affected by specific heat and the
a)         temperature
b)         mass of the substance
c)         volume of the substance
d)         none of the above


h)         a burner on a stove produces
a)         light energy
b)         eat energy
c)         luminous energy
d)         none of the above
i)          what affects how quickly something cools

a)         ambient temperature
b)         material property
c)         thermal contact
d)         none of te above
j)          how can we maximise the rate of energy transfer to keep things cool
a)         we use isothermal process
b)         adiabatic process
c)         isobaric process
d)         none of the above



k)         why does a hot object cool
it losses its energy to the environment
l)          how does surface area affect heat transfer
it is is proportional to the rate of heat transfer, the larger te surface the higher the rate of heat transfer.
m)        what affects how quickly something cools
environmental temperaturre

n)         how does surface area affect heat loss

it is is proportional to the rate of heat transfer, the larger te surface the higher the rate of heat transfer.

o)         the amount of heat required to raise the temperature of 1 gram of a substance by 1°c is called
the specific heat capacity
p)         which factors affect heat transfer between a warm and a cool substance?
the two substance must a thermal contact for te transfer of heat to occur, this is according to the zero law of thermodynamics, which that , if a body A and another body B are at thermal equilibrium with another body C, then both body A and B are also at thermal equilibrium;  thermal equilibrium simply means same temperature,

q)         what must be true about two objects if heat is flowing between them?

 the two substance must a thermal contact for te transfer of heat to occur, this is according to the zero law of thermodynamics, which that , if a body A and another body B are at thermal equilibrium with another body C, then both body A and B are also at thermal equilibrium;
 thermal equilibrium simply means same temperature,

r)          which substance is most likely to heat up the fastest?
a)         water
b)         oil
c)         iron
d)         plastics
s)         a(n) is a material that takes in a wave when the wave hits it.
a)         polarizers
b)         filers
c)         reflectors
d)         radiators
e)         none of the above
t)          is a material that causes a wave to bounce off of it.
a)         filters
b)         reflectors
c)         radiators
d)         none of the above

u)         a diagram that shows thermal energy being released by objects is called a
a)         radiation curve
b)         heat curve
c)         thermal curve
d)         heat graph
v)         which material most likely gets the warmest when placed in the sun?
a)         iron
b)         copper
c)         silver
d)         lead
w)        which best illustrates the way in which radiation transfers thermal energy?
answer this question
x)         examples of heat transfer by radiation
solar energy
y)         examples of convection heat transfer
boiling water , steam engines
z)         examples of conduction convection and radiation in our everyday life
heattransfer in pressing iron for smoothing our cloth is a conduction, boiling egg is convention and electric bulb for lighting our ome is radiations
aa)       5 examples of heat transfer by radiation
I.          electric bulb in lighting our home,
II.        energy from solar radiations
III.       when on hold hand above fire
IV.       electric room warmer
V.       

bb)       which best explains how thermal energy is transferred when someone holds a hand above a fire?
a)         radiation
b)         conduction
c)         convection
d)         none of the above

cc)       which process represents the phase that occurs after a solid melts?
A.        liquid
B.        plasma
C.        solid
D.        gaseous
dd)      when does carbon dioxide absorb the most heat energy?
A.        in nuclear reactor
B.        during respiration in mammals
C.        in carbonated drinks
D.        none of the above
ee)       which energy change occurs during boiling?
energy absorption
ff)        at what temperature does the solid start melting?
a)         boiling point
b)         freezing point
c)         melting point
d)         steam point
gg)       which best explains the relationship between evaporation and temperature?
evaporation and temperature are directly proportionally the higher the temperature the higher the rate of evaporation
hh)       which example involves a phase change in which heat energy is released by the substance?
a)         conduction
b)         solidification
c)         liquefaction
d)         freezing
e)         recombination
ii)         which best describes the energy change that takes place during deposition?
a)         nuclear synthesis
b)         thermo synthesis
c)         decomposition
d)         none of the above
jj)         which arrows represent the phase transitions in which heat energy is gained?
a)         solid →liquid →gas
b)         liquid → gas →solid
c)         solid →gas
d)         gas →solid
e)         all of the above

kk)       electric field lines are drawn away from the positive test charge
 true
ll)         an electric field has strength but not direction
 false
mm)     thomas edison argued that our electrical system should use direct current
true or false
nn)       charging by induction is called
electrostatic influence
oo)       charging by conduction is called
charging by contact.
pp)       the sky appears blue due to the light reflected from the oceans.
false, it is due to scattering the blue spectrum of white light  by air molecules
qq)       a rainbow always appears
answer this question
rr)        the electrical force is much weaker than the force of gravity.
alse, the electric force is about  1039 times greater than gravity.
ss)        electrons move from the power plant to homes in an alternating current.
true
tt)        the unit of electric charge is called a(an)
a)         columb
b)         newton
c)         joules
d)         none of the above
uu)       the unit of electric potential difference between two points is
a)         volt
b)         ampere
c)         ohms
d)         reistivity
vv)       the colors of the visible spectrum can be measured in units of
a)         meter
b)         cm
c)         nanometer
d)         picometer
ww)     farsightedness, or hyperopia, can be corrected with what type lens?
a)         convex
b)         biconvex
c)         plano concave
d)         convex
e)         none of the above
xx)       what are the units of h in the equation e = hf?
a)         joules/hertz
b)         J/S-2
c)         joules-seconds
d)         none of the above
yy)       we explain light today as
a)         waves
b)         particles
c)         energy
d)         all of the above
zz)       polarized light vibrates
in one direction
aaa)      of the following, the electromagnetic wave with the shortest wavelength is
gamma, xray, visible light, microwave
 the shortest waves  is gamma

bbb)     which characteristic of waves of visible light is most similar to waves of microwaves?
a)         interference
b)         reflection
c)         dispersion
d)         none of the above
ccc)      the separation of white light into its component colors is
is called dispersion
ddd)    an overhead fluorescent light bulb would be considered which kind of light source?
a)         luminous
b)         non-luminous
c)         incandescent
d)         none of the above
the shortest of all the radio( em) waves is the
gamma is the shortest

eee)      the sky appears to be blue when the sun is high in the sky because
the  blue spectrum has the longest wavelength
fff)      an optically formed duplicate of an object that has light actually coming from the duplicate is
attempt this question
ggg)     which color of light carries less energy
violet carries least energy, because it has the longest wavelength.


1.         the separation of white light into its component colors is

is called dispersion

2.         the sky appears to be blue because
scattering of the blue spectrum of light by atmospheric particles and airmolecules
3.         a rough surface produces irregular light reflection in which all reflected rays are parallel.
true, laws of relection is obeyed at individual ray level

4.         which statement describes how light behaves when it strikes a translucent material
most of it is scattered in all direction , only small part of it is absorbed, transmitted or reflected
5.         which statement explains why the sky appears blue on a sunny day
scattering of the blue spectrum of light by atmospheric particles and airmolecules
6.         a mirage is created when light is refracted
by a cooler  thinner air molecules
7.         parabolic mirrors eliminate the spherical aberration that is found in spherical mirrors.
true or false
8.         a straw placed in a clear glass of water appears to break at the water’s surface because
refraction of light
9.         which sequence shows the light transmitting capabilities of materials from least to most
opaque → translucent → transparent,  all light impinging on opaque are relected , on transluent are scattered and transparent  transmitted.
10.       how does the scattering of tiny particles in the air affect the colors of the sky
the color of the sky depend on the spectrum of the light scattered , the distance of the sun from the atmospehere.
11.       what an object is made of and the color of light that strikes it determine the
color of the object
12.       why can blue light and yellow light combine to produce white light?
because they are complimentary colors, yellow = green + red,
therefore yellow + blue is same as
 blue + red + green = white light
13.       in order of decreasing light-transmitting capabilities of materials, which is the correct sequence?
opaque → translucent → transparent,  all light impinging on opaque are relected , on transluent are scattered and transparent  transmitted.

14.       the visible light spectrum ranges between
400-700 nanometers
15.       a sunset appears red because
the longest spectrum red is reflected.
16.       an incandescent light bulb produces light when electrons flow through the
neon gas
17.       which kind of light is used to carry information through optical fibers

18.       the primary colors of light are
red. blue and green
19.       michelson calculated the speed of light using
A.        mirror
B.        spring
C.        planet
D.        none of the above
20.       infrared rays have a shorter wavelength than
A.        microwaves
B.        radio waves
C.        tv waves
D.        all of the above

21.       photons travel outward from a light bulb in
neon bulb
22.       which of the following is not true regarding neon lights
23.       a fluorescent light tube usually contains
neon gas

 and attempt the following questions

24.       light acts like
waves and particles at same time, this is called particle-wave duality of light.

25.       cellular telephones utilize
26.       which of the following is not true regarding neon lights?
27.       light moving through a small pinhole does not make a shadow with a distinct, sharp edge because of
28.       radiation transfers thermal energy through .
29.       factors affecting rate of cooling of water
30.       how can the structure of the vacuum flask minimise energy transfer by conduction
31.       which statement accurately describes the flow of heat in each example?
32.       which best explains how radiation is helpful in the plastics industry?
33.       which energy change occurs during boiling?
34.       how does a foam-filled winter coat help keep a person warm?
35.       which explains why conduction is unlikely when ice is placed on a freezer shelf?
36.       which best describes the energy change that takes place during deposition?
37.       which best illustrates the way in which radiation transfers thermal energy?


38.       which is required for convection to occur?
39.       conduction can occur within a single substance, but parts of the substance must have which property?
40.       convection only occurs in .

41.       design an experiment to measure the specific heat capacity of oil
42.       what type of surface is better for a flat roof
43.      

44.       what else does the rate at which energy is transferred depend on
45.      
46.      
47.       which best illustrates the way in which radiation transfers thermal energy?
48.       radiation transfers thermal energy through .
49.      
50.       the photoelectric effect could not be adequately explained with a wave model of light because
51.       photons travel outward from a light bulb in

No comments:

Post a Comment