Question 1
Question
The International System of Units, SI Units, or metrics units of: length, mass, and time are:
Answer

m, kg, min

m, kg, h

ft, slug, s

m, kg, s

cm, g, s
Question 2
Question
The power in SIUnit is measured in Watt, that is related to energy by being equal to
Answer

energy times time

energy consumed

energy wasted

energy times distance

energy per unit time
Question 3
Question
The energy source most used in the United States is
Answer

coal

water

natural gas

oil

biomass (wood)
Question 4
Question
The two factors that influence energy consumption are:
Answer

supply and demand

resource and price

cost and production

lifestyle and efficiency
Question 5
Question
If you started with a $1,600 investment and you had $12,800 after 6 years, what would be the annual interest rate you received?
Question 6
Question
What is the amount of power in kilowatts consumed per capita in the United States?
Question 7
Question
Running a clothes dryer for 90 minutes (1.5 hours) at 1600 Watts will cost about ____ cents if the cost of electricity is 10 cents per kWh:
Answer

4 cents

10 cents

50 cents

24 cents
Question 8
Question
The growth rate of GDP of a certain country is 3.5% per year. This means that the GDP is doubling every ____
Answer

2 years

10 years

5 years

20 years
Question 9
Question
A simple machine, such as a set of pulleys and ropes, known as block and tackle, are devices or tools that multiply appliedforce, and changes its direction, at the expense of:
Answer

speed

velocity

distance

acceleration
Question 10
Question
The following statement is describing which of the three Newton's Laws of Motion? When nonet force is acting is acting on an object, if it is at rest it remains at rest, or if it is in motion, it can only move at a constant velocity.
Answer

First law

Second law

Third law

Law of gravity
Question 11
Question
According to Newton's second law of motion, when a netforce acts on an object, the object must be ____
Question 12
Question
According to Newtons third law, if the push that the car tires give to the roadsurface is the action force, the the reaction force is
Answer

the weight of the car

the force of the car upon the tires

the friction force of the roadsurface on the tires

the acceleration of the car
Question 13
Question
If a 60 kg person is observed to accelerate at the rate of 4 m/s(^2), the net force responsible for this is
Question 14
Question
A car having an initial speed of 9 m/s starts to accelerate at the rate of 4 m/s(^2), the final speed after 5.5 seconds is
Answer

25 m/s

15 m/s

19 m/s

31 m/s
Question 15
Question
A car is moving at 22 m/s (50 mph), when driver sees the traffic light turning red and immediately applies the brakes, decelerating at 6 m/s(^2). What is the car's stopping distance, neglecting the driver's reaction times?
Answer

30.4 m

10.2 m

20.3 m

40.3 m
Question 16
Question
If a stone is dropped from a bridge that is 133 m above the water, how long will it take until the stone hits the water?
Question 17
Question
A ball is projected straight downward with an initial speed of 20 m/s. After 3 seconds, about how fast is it going?
Answer

30 m/s

45.4 m/s

49.4 m/s

60.5 m/s
Question 18
Question
A ball is projected straight up at an initial speed of 24.5 m/s. After 2.5 seconds, what is it's speed?
Answer

9.8 m/s

14.7 m/s

4.9 m/s

0 m/s
Question 19
Question
How much work is required to increase the velocity of a 4 kg car from rest to 5 m/s?
Question 20
Question
The gravitational potential energy of an object, near the Earth's surface, and the work done to lift the object to the height "h" is given by
Answer

weight times height

mass times height

mass times speed

mass times acceleration
Question 21
Question
From workKE theorem, what is the speed of a car of mass 2500 kg, after it is pushed by a force of 500 N over a horizontal distance of 10 m?
Question 22
Question
When a car is braked to a stop, it's kinetic energy is transformed into
Answer

stopping energy

energy of motion

potential energy

heat energy
Question 23
Question
Our nose cracker moved back and forth as shown. The kinetic energy will be greatest at what point?
(A > B > C)
Answer

A

B

A and C

halfway between A and B
Question 24
Question
The efficiency of a lightbulb is the ratio of the
Answer

energy input to the energy out of the bulb

light output of the bulb to the electrical energy input

heat energy out to the electrical energy in

voltage output of the bulb to the power input
Question 25
Question
If the energy conversion efficiencies in a 3 step process are 36% for the first step, 44% for the second, and 26% for the third, the overall efficiency is about:
Question 26
Question
For a fossil fueled electrical generating plant, 10,000 Btus of chemical energy input into the plant will result in about how many Btus of waste heat dumped into the environment if the efficiency of power plant is 35%?
Answer

8,800 Btus

10,000 Btus

4,080 Btus

6,500 Btus
Question 27
Question
The first law of thermodynamics states that: heat added to the system, plus work done on the system, equals change in the total energy of the system. This statement is based on
Answer

how heat can be conducted

how temperature is increased

the principle of conservation of energy

the state of the system
Question 28
Question
The second law of thermodynamics states that heat energy flows in the direction of
Answer

up, since heat rises

higher temperature

lower temperature

lower entropy
Question 29
Question
The total Rvalue of a wall made of different layers of materials is obtained by
Answer

multiplying the R values of each layer

the sum of R values for each layer

sum of areas of each layer

sum of thicknesses of each layer
Question 30
Question
When ice crystals form in the clouds,
Answer

phase change from solid to liquid occurs

the thermal mass of the atmosphere increases

heat energy is released

the atmosphere becomes colder
Question 31
Question
The Rvalue of material is not related to its
Answer

composition

area

thickness

resistance to heat flow
Question 32
Question
An object with a very high specific heat will
Question 33
Question
The efficiency of an electric motor is the ratio of the
Answer

energy into the motor to the energy out of it

heat released to rotational energy

heat plus electricity produced to the electrical input

shaft work output to the electrical energy input
Question 34
Question
For a furnace to provide 80,000 Btu/h of thermal energy to a living space, what should the rate of heat supplied by the fuel be if the furnace efficiency is 65%?
Answer

103,000 Btu

15,300 Btu

123,000 Btu

223,000 Btu
Question 35
Question
A heat engine ____
Answer

converts work into heat energy

can be 100% efficient in the absence of friction

can have no cold sink

needs a hot source and a cold sink to be able to work
Question 36
Question
The heat transfer by conduction through an area 10ft x 7ft section of the wall, with Rvalue of 35 (ft^2Fh/Btu), with temperature difference between the sides change in temperature equaling 10 degrees farenheit, will be
Answer

10 Btu/h

35 Btu/h

15 Btu/h

20 Btu/h
Question 37
Question
Since the rate of heat transfer by conduction is proportion to the change in temperature, what percent savings in your cooling bill would you expect if you turned the thermostat up from 70 degrees to 74 degrees, and the outside temperature is 95 degrees?
Question 38
Question
Thermal radiations are electromagnetic waves and like all EM waves are of the type
Answer

transverse waves

longitudinal waves

surface waves

torsional waves
Question 39
Question
Normally the phase changes from vapor to liquid to solid takes place in that order when the heat is
Answer

kept constant

pressure is reduced

added

removed
Question 40
Question
85 degrees Fahrenheit is equal to ____ temperature in Kelvin scale
Question 41
Question
The Carnot efficiency (maximum possible efficiency) of a heat engine operating between 20 degrees C and 2000 degrees C will be about ____. (Note: the temperature must be in Kelvins > C + 273)
Question 42
Question
A heat pump will have an efficiency of about ____
Question 43
Question
What are the percentages of InfraRed (IR), Ultra Violet (UV), and Visible Light in the solar radiation at the top of the Earth's atmosphere?
Answer

17% IR, 37% UV, 46% visible

37% IR, 5% UV, 58% visible

51% IR, 12% UV, 37% visible

47% IR, 7% UV, 46% visible
Question 44
Question
The amount of infrared radiation emitted, or absorbed, by an object, apart from the temperature difference with the surroundings, and the surface area, depends also on
Answer

shape

color, surface texture

its type of material

density
Question 45
Question
What is the wavelength of the electromagnetic waves emitted by a SatelliteTV, that has typically a frequency of 12 GHz? (GHz= 10^9 Hz)
Answer

0.015 m

0.025 m

0.035 m

0.013 m
Question 46
Question
Specific heat of a substance is defined as the
Answer

heat required to increase its temper by onedegree Fahrenheit

heat required to increase its temperature by onedegree Celsius

heat required to increase its heat by one joule

heat required to increase the temperature one one unite mass by one degree
Question 47
Question
How much heat energy is required to increase the temperature of 3 kg of water from room temperature of 20 degrees C to the boiling point 100 degrees C? (Specific heat of water in SI units is C= 4186 J/kg*C)
Answer

20.4 kJ

50.6 kJ

100.5 kJ

789.7 kJ
Question 48
Question
What produces the cooling in a refrigerator?
Answer

evaporation of Freon outside

compression on Freon inside

condensation of Freon

evaporation of Freon inside
Question 49
Question
The geothermal heat, that is, the heat from the interior of the earth, can be used to warm or cool a house
Question 50
Question
A wall of a typical house is made of six layers with Rvalues given in (ft^2 F  h/Btu); from interior dead air later (R1= 0.68), 0.5 in sheetrock (R2= 0.45), 5.5 in fiberglass insulation (R3= 19), 0.5 in plywood (R4= 0.63), exterior dead air layer (R5 = 0.68). If temperature difference between outside and inside is 22 degrees F, and the total area of the wall is 360 ft^2 the rate of heat transfer by conduction is ____.
Answer

567.4 Btu/h

156.3 Btu/h

369.4 Btu/h

423.6 Btu/h
Question 51
Question
The Carnot efficiency of a heat engine operating between 21 degrees C and 1200 degrees C will be about
Question 52
Question
Amount of heat and temperature of an object are different because amount of heat depends on the
Answer

temperature difference

energy of its molecules

size of its molecules

amount of substance
Question 53
Question
The first law of thermodynamics is related to the
Answer

conservation of energy

heat and temperature

entropy and temperature

heat and work
Question 54
Question
To keep an iced drink cold for the longest time, what color cup would you use?
Question 55
Question
Suppose it takes 48,000 Btu to heat up the water in a tank. If the heating element has an output of 2,800 W, then how long will it take to heat up the water, assuming no extra heat losses?
Question 56
Question
The existence of the four seasons, in the midlatitude locations, is due to the
Answer

moonearth interaction

variation of the sunearth distance

tilt of rotation axis of the earth by 23.5 degrees

variation of the moonearth distance
Question 57
Question
Heat transfers by all three ways; conduction, convection, and radiation; are directly proportional to the....
Answer

surface temperature

surface roughness

surface color

surface area
Question 58
Question
The optimal angle of tilt, from the horizontal, for a south facing flatplate solar collector, or photovoltaic cells panel, in a location with the latitude of 50.5 degrees N, for the purpose of solar panels installation is
Answer

50.5 degrees

60.5 degrees

20.5 degrees

30.5 degrees
Question 59
Question
What is the main advantage of using thermal mass, in the form of thick concrete floor, or Trombe wall, in a directgain passive solar system?
Answer

to increase temperature fluctuations during the night

to provide foundation support for the collector superstructure

to increase the insolation on southfacing windows

to reduce temperature fluctuations during the day
Question 60
Question
During what season will more insolation be delivered to a vertical southfacing window on a clear day?
Answer

fall

winter

spring

summer
Question 61
Question
The insolation in a certain location is 900 W/m^2 and 85% of this is direct component on the collector. If a useful rate of energy needed for cooking is 150 W, then what area of the solar collector oven in the form of parabolic mirror is needed to intercept this amount of radiation, take the efficiency to 20%?
Answer

0.98 m^2

1.2 m^2

1.6 m^2

0.87 m^2
Question 62
Question
Determine the collector area needed to heat 554 lbs of water (80 gallons), in one day, from 50 degrees F to 130 degrees F, if the insolation is 1700 Btu/d/ft^2 and the FPC efficiency is 48%.
Answer

54 ft^2

62 ft^2

73 ft^2

33 ft^2
Question 63
Question
The main difference between transverse and longitudinal waves is that transverse waves
Question 64
Question
A typical microwave generates the electromagnetic waves of frequency 2.45 GHz (1 Giga= 10^9). The wavelength of the radio wave corresponding to the frequency is
Answer

9.26 cm

8.48 cm

11.45 cm

12.24 cm
Question 65
Question
In prospection for ore by gravimetric method, (to measure the variation of g=9.8 m/s^2 on the earths surface at a fixed height) how do you distinguish between petroleum and ore?
Answer

g would be greater over an ore deposit than a petroleum deposit

density of ore is less than petroleum

g does not change over the surface of the earth

g would be greater over a petroleum deposit than an ore deposit
Question 66
Question
When seismic waves (or light waves) travel from one medium into another medium with different wavespeed, what is the difference between reflection and refraction, at the interface between the two media?
Answer

Refracted wave bends and goes through the second medium

reflection and refraction are the same effect

reflection can only occur on a smooth interface

refraction will not bend the direction of the waves
Question 67
Question
What is the main difference between electromagnetic waves and sound waves?
Answer

electromagnetic waves can travel in a vacuum

sound waves travel faster

sound waves can be polarized

sound waves can travel in a vacuum
Question 68
Question
The magnitude of gravitational attraction between a 135 kgperson and a 290,000 kgdoor of a bunker, with 0.2 m distance between their centers of mass is ____. (G= 6.674 x 10^11 n*m2/kg2)
Answer

6.53 x 10^2 N

7.64 x 10^3

8.75 x 10^3

5.42 x 10^2
Question 69
Question
In a fractionating tower of an oilrefinery, where crude oil is heated from the bottom to separate different hydrocarbon constituents, what is the least volatile constituent of crude oil? That is, the component with the highest boiling point?
Answer

industrial fuel oil

kerosene

gasoline

asphalt
Question 70
Question
The longevity of a fossilfuel reserve is determined by the ratio of
Answer

proven reserves/ daily production production rate

proven reserves / yearly production rate

indicated reserves / yearly production rate

inferred reserves yearly production rate
Question 71
Question
Pressure on a surface inside a fluid is due to the
Question 72
Question
Static pressure at a depth h below the surface of a fluid is given by
Answer

mass x g x h

density x g x h

force x time x h

h x g x volume
Question 73
Question
A swimming pool has a depth of 2.5 m. What is the gauge pressure at the bottom of this pool, in psi? (Density of water is pw= 1000 kg/m3)
Answer

3.553 psi

4.652 psi

7.324 psi

1.334 psi
Question 74
Question
The normal blood pressure is expressed as 80 to 120 mmofmercury, which are gauge pressure values. When these values are converted into psi they become ____
Answer

1.432, 2.133 psi

1.547, 2.320 psi

1.652, 2.358 psi

1.321, 2.142 psi
Question 75
Question
A balloon in the air is buoyed up by a force equal to the
Answer

weight of the air it displaces

weight of the balloon and its contents

mass of air displace

density of the surrounding air
Question 76
Question
What is the buoyant force on a 3 ton ship that is floating in the sea?
Answer

2.5 tons

3.0 tons

3.5 tons

1.5 tons
Question 77
Question
Why do you expect photochemical smog to be a greater problem in a city like Los Angeles than in a heavily industrialized city like Pittsburgh?
Answer

LA has more automobile traffic

LA gets more days with temperature inversion

LA is less windy

Pittsburg has more desulfurization plants
Question 78
Question
The acidity of rain, or other solutions, is measured by the pH number scale that varies from 0 to 14. What does a pH number represent?
Answer

10 to the positive power of the hydrogen ion concentration

the larger the pH number the stronger the acidity

the smaller the pH number the less acidic the solution is

10 to the negative power of the hydrogen ion concentration in the solution
Question 79
Question
The pressure exerted on your finger if you hold up a 15 lb box of apples, if the contact surface of your finger is 0.25 in x 0.25 in, would be ____
Answer

200 psi

220 psi

240 psi

160 psi
Question 80
Question
Suppose it takes 38,500 Btu to heat up water in a tank. If the heating element has an output power of 2,500 W, then how long would it take to heat up the water, assuming no extra heat losses? (1 Btu= 1055 Joules, 1 Watt = 1 Joule per second, 1 hour = 3600 s)
Answer

55 mins

2.5 hours

3.5 hours

4.5 hours
Question 81
Question
During which season will more insolation be delivered to a vertical south facing window on a clear day?
Answer

Winter

Fall

Spring

Summer
Question 82
Question
The optimum angle of tilt from the horizontal, for a flat plate solar collector, or panels of photovoltaic cells, both facing South, in a location with a latitude of 50.5 degrees North, for the purpose of solar panel installations is
Answer

30.5 degrees

40.5 degrees

50.5 degrees

60.5 degrees
Question 83
Question
The measure of the angle of position of the sun from the South direction is called the
Answer

altitude

azimuth

declination

inclination
Question 84
Question
If the insolation (I) upon a flat plate collector is 890 (Btu/ft2*day), how large must the area A of the collector be to provide (Q/t= 12,400 Btu/hr of thermal energy for one day (24 hours)? Take the collector efficiency to be 57.5% (Note: Btu/h is related to I A and E by Q/t = I*A*E)
Answer

18 ft2

164 ft2

376 ft2

637 ft2
Question 85
Question
The acidity of rain, or a solution, is measured by the pH number, that varies from 0 to 14, what does a pH number represent?
Answer

10 to the positive power represent the hydrogen ion concentration per mole

the larger the pH the stronger the acidity of the solution

10 to the negative power of the hydrogen ion concentration per mole in the solution

the smaller the pH the less acidic the solution
Question 86
Question
Pressure on a surface is defined as
Answer

mass x speed

mass x velocity

density x volume

force per unit area
Question 87
Question
Pressure on a surface inside a fluid is caused by
Answer

weight of fluid molecules

force of gravity

potential energy of fluid molecules

repeated knocking of the fluid molecules on the surface
Question 88
Question
Static pressure at a depth h in a fluid is given by
Answer

h x g x volume

mass x g x h

force x time x h

density x g x h
Question 89
Question
Atmospheric pressure, at sea level, is 14.7 psi, the gauge pressure of an automobile tire is 38 psi, the absolute pressure of this tire in Pascal is..... (Note: 1 psi = 6895 Pa)
Answer

131,100 Pa

248,200 Pa

353,300 Pa

363,400 Pa
Question 90
Question
A balloon in the air is buoyed up by a force equal to the ___
Answer

density of the surrounding air

atmospheric pressure

weight of the balloon and its contents

weight of the air it displaces
Question 91
Question
Which of the following air pollutants is emitted in about equal amounts by stationary and mobile sources?
Answer

particulates

carbon monoxide

nitrogen oxides

sulfur dioxides
Question 92
Question
Ozone layer in the stratosphere
Answer

dissipates within days

combines with NO or NO2 to produce smog

absorbs infrared light from the sun

provides protection from incoming UV solar radiation
Question 93
Question
How much has the global temperature on earth changed over the past 100 years?
Answer

0.5 degrees C

1.0 degrees C

1.5 degrees C

2.0 degrees C
Question 94
Question
One of the fundamentals of electrostatic is that the force between two unlike charges is
Answer

repulsive

neutralized

attractive

zero
Question 95
Question
Electricity is transmitted from plower plants at ____ to reduce by Joule heating in the transmission lines, which is about 10%.
Answer

high currents

low resistance

high resistance

high voltage
Question 96
Question
What quantity is the same for three resistors in a series circuit?
Answer

power

resistance

current

voltage
Question 97
Question
What quantity is the same for three resistors in a parallel circuit?
Answer

power

resistance

current

voltage
Question 98
Question
A circuit consists of one lightbulb of resistance of 144 ohms and another lightbulb of 240 ohms that are wired in series to a 120 V wall socket outlet. What is the current through this circuit?
Answer

0.10 A

0.20 A

0.30 A

0.40 A
Question 99
Question
Two resistors of 144 ohms and 240 ohms are wired in parallel to 120 V wall outlet socket outlet, the current through the 240 ohm resistor will be
Question 100
Question
The electrostatic force of attraction between two charges of q1= 35 x 10^6 C and q2 = +69 x 10^6 C, separated by a distance of 3 m is ___
Answer

0.4 N

1.21 N

2.41 N

3.53 N
Question 101
Question
A high temperature superconductor compounds such as YBCO ____
Answer

provides large magnetic fields at room temperature

has no resistance at room temperature

has no electrical resistance below its critical temperature

generates constant voltage at low temperatures
Question 102
Question
A lightbulb draws a current of 2.5 amps, when connected to a wall outlet of 120 V. What is the resistance of the bulb?
Answer

50 ohms

100 ohms

200 ohms

300 ohms
Question 103
Question
The resistance of four light bulbs are given below. Which one has the highest wattage?
Answer

144 ohms

192 ohms

240 ohms

320 ohms
Question 104
Question
How much current is drawn by 3240 W electrical appliance operating at 240 V?
Answer

11.3 A

12.4 A

13.5 A

14.5 A
Question 105
Question
What is the cost of running your water heater of power rating 2800 W for 2.5 hours per day, for one year or 365 days, if the electricity costs 12 cents per kWh?
Question 106
Question
The magnetic field of a bar magnet is similar to that produced by
Answer

a horse shoe magnet

a straight current carrying wire

two coils separated by long distance

a current carrying solenoid
Question 107
Question
Alternating current has an advantage over direct current because
Answer

batteries can be displaced in most circuits

electrical generators can be made

produces no heat loss

one can step up, or down, the amount of voltage used
Question 108
Question
A transformer (adaptor) can only operate if
Answer

the power in equals the power out

an alternating current is used

the potential difference is large enough

we step down the current
Question 109
Question
If the current through a 33 ohm resister and a 57 ohm resistor in series is 5 A, then the total voltage drop across both of these resistors will be
Question 110
Question
What transformer turnsratio of secondary to primary is required to lower the voltage from 120 V wall socket outlet to 8 V for charging a cell phone?
Question 111
Question
A bird sitting on a bare high voltage wire is not electrocuted because ____
Answer

of the high resistance of its body

its body is at a low electrical potential compared to the wire

the high voltage across its feet produced a small current

there is no electrical potential difference across its body because the other wire is out of reach
Question 112
Question
For a photovoltaic cell of 0.5 V and of area 1 cm2, the maximum output power is 135 mW (mW= 10^3 W). What is the current provided by this cell?
Answer

0.01 A

0.02 A

0.23 A

0.27 A
Question 113
Question
The site location for a wind turbine is especially important. If the power output goes as the cube of the wind velocity, then which of the following average velocities will give approximately 8 times as much output as 10 mph winds?
Answer

5 mph

10 mph

15 mph

20 mph
Question 114
Question
If the average wind speed for 24 hours is 16 mph at one site but 13 mph at another site for 12 hours and then 23 mph for 12 hours at another site, how much output can be expected from the first turbine compared to the turbine at the second site?
Question 115
Question
A 1000 MW power plant is shut down for one day (24 hours). What is the loss of income from this plant if the selling price were 10 cents/kWh (1 MW=10^6 kW).
Answer

$180,000

$700,000

$2,400,000

$3,500,000
Question 116
Question
For the following circuit, with all the bulbs identical, what is true for the brightness of the lights?
l l (A)
l l_____
l (B) l l (C)
l _______ l ____ l
Answer

A = B = C

A = 4B = 4C

A = .5B = .5C

A = B, C = 0
Question 117
Question
The existence of atom was proposed by Democritus (420 BCE) and at the beginning of the 19th century, John Dolton proved that every element has an atom, by the ____
Question 118
Question
The discovery of atomic nucleus was made by firing fast moving ____ at a thin gold foil
Answer

alpha particles

gamma rays

electrons

neutrons
Question 119
Question
The isotopes of an element all have the same number of
Answer

protons

electrons

positron neutrons

nucleons
Question 120
Question
For the same energy, the most penetrating type of radiations are
Answer

Bparticles

Xrays

aparticles

yrays
Question 121
Question
The halflife of a radioactive nuclide is the time taken for _____
Answer

half of its neutrons to decay

half of its electrons to decay

half of its mass to decay

half of its nuclei to decay
Question 122
Question
At 9 am on Monday, a radioactive sample contained 80 million nuclei. At 9 am on Saturday, 2.5 million of these nuclei are left over and has not decayed. The half life of the sample is
Answer

1.5 days

1 day

5 days

4 days
Question 123
Question
The radioactive isotope Cobalt60 decays into Nickel60 by beta emission, with a half life of 5.3 years. If we start with 100 gram of Co60, after how many years will we have only 390 milligrams of it left?
Question 124
Question
The activity of Carbon14 in the living organism today is 15.3 disintegrations per minute, per gram. Halflife of Carbon14 is 5730 years. If the activity of an archaeological sample, due to the carbon14 is 3.825 disintegrations per min, per gram, how old is the sample?
Question 125
Question
The binding energy of a Helium nucleus is 4.5 x 10^12 Joules (28.4 MeV). What is the total binding energy of 4grams (one mol.) of Helium that has avogadro's number NA= 6.02 x 10^23 of nuclei, when this mass is converted into radiant energy in the interior of the Sun?
Answer

1.7 x 10^11 J

2.7 x 10^12 J

1.2 x 10^10 J

3.4 x 10^13 J
Question 126
Question
The pair production and annihilation refer to the simultaneous production of a particle and its antiparticle by two energetic gammaray photons, near a nucleus, and the destruction of a particle and an antiparticle, as a result of collision between them, these particles and antiparticles can be _____
Answer

electron and positron

proton and electron

proton and neutron

two neutrons
Question 127
Question
In the following fission reaction, the atomic number Z and mass number of nucleus A of the unknown element Y are:
(0/1)n + (92/235)U > (53/135)I + (Z/A)Y + (0/2)n
Answer

38, 102

39, 99

39, 100

37, 100
Question 128
Question
If a lightweight stable nucleus has 12 neutrons, the atomic mass is expected to be _____. (1 atomic mass unit = 1.66 x 10^27 kg).
Answer

18 amu

24 amu

36 amu

6 amu