HS Sample Set 7, Round 15 from NSB
Which of the following is a proper comparison between ductile and brittle fracture? W) Ductile has an unstable crack and brittle has a stable crack X) Brittle has relatively little plastic deformation, while ductile has extensive deformation Y) Brittle doesn’t occur in cold metals while ductile does Z) Brittle fracture is preferred in most applications
W: W) Ductile has an unstable crack and brittle has a stable crack
X: X) Brittle has relatively little plastic deformation, while ductile has extensive deformation
Y: Y) Brittle doesn’t occur in cold metals while ductile does
Z: Z) Brittle fracture is preferred in most applications
Answer: X) X) Brittle has relatively little plastic deformation, while ductile has extensive deformation
The generation of proteolytic fragments is essential to protein purification. Chymotrypsin is an endopeptidase that will cleave peptide amide bonds. Name two of the four amino acids this enzyme cleaves.
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What is the slope–intercept form of the equation of the line that is tangent to the circle with equation \(x^2 + y^2 = 25\) at the point \((-3, 4)\)?
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Given the two sequences \(s_1\) with \(n\)th term \(\displaystyle \tfrac{2}{n+6}\) and \(s_2\) with \(n\)th term \(\displaystyle \tfrac{n}{5+n}\), which of the following statements is correct? W) \(s_1\) and \(s_2\) are both increasing X) \(s_1\) is increasing and \(s_2\) is decreasing Y) \(s_1\) is decreasing and \(s_2\) is increasing Z) \(s_1\) and \(s_2\) are both decreasing
W: W) \(s_1\) and \(s_2\) are both increasing
X: X) \(s_1\) is increasing and \(s_2\) is decreasing
Y: Y) \(s_1\) is decreasing and \(s_2\) is increasing
Z: Z) \(s_1\) and \(s_2\) are both decreasing
Answer: Y) Y) \(s_1\) is decreasing and \(s_2\) is increasing
Which of the following pairs of metamorphic rocks both result from the parent rock shale? W) Slate and hornfels X) Greenstone and phyllite Y) Quartzite and amphibolite Z) Marble and gneiss
W: W) Slate and hornfels
X: X) Greenstone and phyllite
Y: Y) Quartzite and amphibolite
Z: Z) Marble and gneiss
Answer: W) W) Slate and hornfels
Wolf–Rayet stars are young, massive stars with prodigious mass loss rates. What force drives their strong stellar winds?
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According to the Standard Model, protons and neutrons are made of quarks. What are the quark constituents of protons?
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What famous nuclear reaction bypasses the “mass-8 gap” in stellar burning and proceeds mainly through the Hoyle state in carbon-12?
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In northern climates, which component of a residential home, if properly insulated, will lead to maximal energy savings?
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In string theory, in the absence of external interactions, string dynamics are governed by tension and which of the following types of energy? W) Kinetic X) Chemical Y) Electrostatic potential Z) Gravitational potential
W: W) Kinetic
X: X) Chemical
Y: Y) Electrostatic potential
Z: Z) Gravitational potential
Answer: W) W) Kinetic
The basal lamina is a long thin structure that is essential for the stability of body cells. Which of the following cell classes is NOT typically underlain or surrounded by the basal lamina? W) Epithelial X) Muscle Y) Nerve Z) Cartilage
W: W) Epithelial
X: X) Muscle
Y: Y) Nerve
Z: Z) Cartilage
Answer: Z) Z) Cartilage
When using a light microscope to view a stained cross section of a dorsal root ganglion, which of the following structures are you most likely to see? W) Cell bodies of sensory neurons X) Axons of sensory neurons Y) Axons of motor neurons Z) Cell bodies of motor neurons
W: W) Cell bodies of sensory neurons
X: X) Axons of sensory neurons
Y: Y) Axons of motor neurons
Z: Z) Cell bodies of motor neurons
Answer: W) W) Cell bodies of sensory neurons
Bottom-up approaches to nanotechnology generally involve microscopy. What technique is primarily involved in the top-down approach?
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The molecule (2E,4Z,6E)-2,4,6-octatriene can isomerize to cis-5,6-dimethyl-1,3-cyclohexadiene. Identify: 1) The family of pericyclic reactions for this isomerization 2) The mode of activation 3) The direction of stereochemical rotation
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If the graph of the complex number \(z = 3 + 4i\) is rotated \(90^\circ\) counterclockwise, what complex number is represented by the result?
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Which of the following is a solution for \(x\) of the equation \(2^{\,x-2} = \pi^x\)? W) \(\dfrac{\ln(4)}{\ln(2) - \ln(\pi)}\) X) \(\dfrac{\ln(4)}{\ln(\pi) - \ln(2)}\) Y) \(\dfrac{\ln(\pi) - \ln(2)}{\ln(4)}\) Z) \(\dfrac{\ln(2) - \ln(\pi)}{\ln(4)}\)
W: W) \(\dfrac{\ln(4)}{\ln(2) - \ln(\pi)}\)
X: X) \(\dfrac{\ln(4)}{\ln(\pi) - \ln(2)}\)
Y: Y) \(\dfrac{\ln(\pi) - \ln(2)}{\ln(4)}\)
Z: Z) \(\dfrac{\ln(2) - \ln(\pi)}{\ln(4)}\)
Answer: W) W) \(\dfrac{\ln(4)}{\ln(2) - \ln(\pi)}\)
A halo around the Sun or Moon is different than a corona around the Moon in that the halo is produced by what? W) Water droplets in a cloud X) Ice crystals in a cloud Y) Reflection of sunlight Z) Refraction of sunlight
W: W) Water droplets in a cloud
X: X) Ice crystals in a cloud
Y: Y) Reflection of sunlight
Z: Z) Refraction of sunlight
Answer: X) X) Ice crystals in a cloud
Radial velocity surveys are biased towards discovering which of the following kinds of exoplanets? W) Face-on systems close to the Earth X) High albedo planets with large semi-major axes Y) Systems with large mass ratios that are close to the Earth Z) Edge-on systems with small semi-major axes
W: W) Face-on systems close to the Earth
X: X) High albedo planets with large semi-major axes
Y: Y) Systems with large mass ratios that are close to the Earth
Z: Z) Edge-on systems with small semi-major axes
Answer: Z) Z) Edge-on systems with small semi-major axes
If 500 joules of energy are required to move a 20-coulomb charge from point A to point B, what must be the potential difference, in volts, between A and B? W) 0 X) 25 Y) 1000 Z) 10000
W: W) 0
X: X) 25
Y: Y) 1000
Z: Z) 10000
Answer: X) X) 25
A child is playing on a straight metal slide which is at 45° to the level ground. The child slides down the slide in twice the time it would take if the slide was completely frictionless. What is the coefficient of kinetic friction of the slide?
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In mammals, B cells are produced in the bone marrow. What cloacal organ in birds produces these cells and is the source of their name?
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You are walking at night on a sandy beach in southern California during a high tide that followed the last full moon. What fish will you most likely see mating in the sand on the beach during your walk?
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Which of the following is NOT a method to separate two liquids? W) Fractional distillation X) Chromatography Y) Sonication Z) Extraction
W: W) Fractional distillation
X: X) Chromatography
Y: Y) Sonication
Z: Z) Extraction
Answer: Y) Y) Sonication
The intensity of absorption maxima in a visible spectrum depends upon which of the following characteristics? W) Ligand field splitting parameter X) Allowedness of the transitions Y) Electron configuration of the metal center Z) Degree of inter-electron repulsion
W: W) Ligand field splitting parameter
X: X) Allowedness of the transitions
Y: Y) Electron configuration of the metal center
Z: Z) Degree of inter-electron repulsion
Answer: X) X) Allowedness of the transitions
Which of the following is a consequence of Gauss’s law for magnetism? W) A changing magnetic flux through a loop creates an electric current around the loop X) Charges must be moving to produce magnetic fields Y) A time-varying electric flux acts as a current and produces a magnetic field Z) Magnetic monopoles do not exist
W: W) A changing magnetic flux through a loop creates an electric current around the loop
X: X) Charges must be moving to produce magnetic fields
Y: Y) A time-varying electric flux acts as a current and produces a magnetic field
Z: Z) Magnetic monopoles do not exist
Answer: Z) Z) Magnetic monopoles do not exist
Which of the following three choices has the longest period: 1) A pendulum on Earth with a cord length of 3 m, 2) A pendulum on the Moon (g ≈ 1.6 m/s²) with a cord length of 1 m, 3) A pendulum on Jupiter (g ≈ 26 m/s²) with a cord length of 10 m?
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A jar contains 500 jellybeans, 100 each of red, white, blue, orange, and green. If you reach in without looking, how many jellybeans must you grab to be certain that at least five are of the same color? W) 6 X) 21 Y) 25 Z) 26
W: W) 6
X: X) 21
Y: Y) 25
Z: Z) 26
Answer: X) X) 21
Find \(h(t)\) if \(2h'(t) - h(t) = 0\) and \(h(0) = 10\).
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What is the term for the process through which precipitation forms in water vapor clouds?
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Imagine a parcel of air forced upward. If the environmental lapse rate is greater than the dry adiabatic rate, what is the vertical motion of the parcel?
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What is the process by which lithium enters electrodes in a lithium-ion battery? W) Intercalation X) Precipitation Y) Hydration Z) Bombardment
W: W) Intercalation
X: X) Precipitation
Y: Y) Hydration
Z: Z) Bombardment
Answer: W) W) Intercalation
While walking down the street, an open wire falls on you and you receive an instantaneous alternating-current electric shock. Where did most of the electrons come from that “shocked” you? W) The ground X) The wire Y) The air Z) Your body
W: W) The ground
X: X) The wire
Y: Y) The air
Z: Z) Your body
Answer: Z) Z) Your body
A square loop of wire with a resistance of 2 Ω and a side length of 2 m has a magnetic field of 5 T passing through it. If the field is uniformly reduced to zero in 10 s, what is the magnitude of the current generated in the loop in amperes? W) 0.5 X) 1 Y) 2 Z) 4
W: W) 0.5
X: X) 1
Y: Y) 2
Z: Z) 4
Answer: X) X) 1
A rod of length 1 m and mass 2 kg is pivoted perpendicularly to its length through its center of mass. If two point masses, each of mass 1 kg, are attached to each end of the rod, what is the total moment of inertia (in kg·m²) of this collection?
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Which of the following proteins would likely be synthesized by a cytosolic ribosome instead of an ER-bound ribosome? W) Insulin X) Actin Y) Subunits for a potassium channel Z) G protein–coupled receptor
W: W) Insulin
X: X) Actin
Y: Y) Subunits for a potassium channel
Z: Z) G protein–coupled receptor
Answer: X) X) Actin
The mechanism of action of the antiviral drugs zanamivir and oseltamivir is to inhibit what virally encoded enzyme expressed on the surface of influenza virions? W) Neuraminidase X) Hemagglutinin Y) Nonspecific protease Z) Reverse transcriptase
W: W) Neuraminidase
X: X) Hemagglutinin
Y: Y) Nonspecific protease
Z: Z) Reverse transcriptase
Answer: W) W) Neuraminidase
Which of the following reactions would be most expected to form a racemic product mixture? W) E1 X) E2 Y) SN1 Z) SN2
W: W) E1
X: X) E2
Y: Y) SN1
Z: Z) SN2
Answer: Y) Y) SN1
At the beginning of an experiment measuring the phosphorescence produced by a phosphorescent substance, the brightness is measured at 12 lumens. After five minutes, the brightness is 6 lumens. After 10 minutes, it is 4 lumens. What brightness, in lumens, would you expect to find after 15 minutes?
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Box A contains 4 chips numbered 1 through 4 and Box B contains 5 chips numbered 1 through 5. A chip is drawn from each box and the product of the two values drawn is denoted by \(x\). What is the probability that \(x\) is even? W) 1/2 X) 2/3 Y) 7/10 Z) 3/4
W: W) 1/2
X: X) 2/3
Y: Y) 7/10
Z: Z) 3/4
Answer: Y) Y) 7/10
Find an antiderivative for \(y = x e^{-x}\).
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In the lipid membranes of cells, there are multipass proteins that are partly within the lipid bilayer and partly outside of the lipid bilayer. Through which of the following forces do these proteins achieve this position relative to the membrane? W) Covalent linkages to lipid molecules X) Disulfide bonds to lipid molecules Y) Hydrophobic and hydrophilic interactions Z) Physical connections to the cytosol
W: W) Covalent linkages to lipid molecules
X: X) Disulfide bonds to lipid molecules
Y: Y) Hydrophobic and hydrophilic interactions
Z: Z) Physical connections to the cytosol
Answer: Y) Y) Hydrophobic and hydrophilic interactions
What is the term for the pattern of arrangement of embryonic leaves within the bud?
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Which of the following volcanic hazards can have worldwide climatic consequences? W) Lahars X) Pyroclastic flows Y) Volcanic tremors Z) Volcanic tephra
W: W) Lahars
X: X) Pyroclastic flows
Y: Y) Volcanic tremors
Z: Z) Volcanic tephra
Answer: Z) Z) Volcanic tephra
During the middle Cenozoic era, South America separated from Antarctica and a circumpolar current formed. Which of the following was NOT caused by this separation? W) A permanent ice cap formed on Antarctica X) The temperature gradient lessened between the South Pole and the Equator Y) Earth’s average temperature decreased Z) Thermohaline circulation of the southern hemisphere Atlantic Ocean intensified
W: W) A permanent ice cap formed on Antarctica
X: X) The temperature gradient lessened between the South Pole and the Equator
Y: Y) Earth’s average temperature decreased
Z: Z) Thermohaline circulation of the southern hemisphere Atlantic Ocean intensified
Answer: X) X) The temperature gradient lessened between the South Pole and the Equator
A simple pendulum is pulled back to a large angle less than 90°, so that the small-angle approximation is no longer valid. Which of the following statements is true about the period of oscillation of the pendulum? W) It is independent of the amplitude X) It is larger than the small-angle approximation Y) It is smaller than the small-angle approximation Z) It depends on the square root of the amplitude
W: W) It is independent of the amplitude
X: X) It is larger than the small-angle approximation
Y: Y) It is smaller than the small-angle approximation
Z: Z) It depends on the square root of the amplitude
Answer: X) X) It is larger than the small-angle approximation
A motor has a DC resistance of 5 Ω. The motor operates on 220 V AC, and when running at full speed, it generates a back electromotive force of 200 V. What is the current, in amperes, drawn when the motor operates at top speed? W) 0.4 X) 4 Y) 40 Z) 44
W: W) 0.4
X: X) 4
Y: Y) 40
Z: Z) 44
Answer: X) X) 4
Whose equation describes the relationship between the concentration of an electro-active species and electric potential? W) Ohm X) Joule Y) Nernst Z) Bode
W: W) Ohm
X: X) Joule
Y: Y) Nernst
Z: Z) Bode
Answer: Y) Y) Nernst
Arrange the following four substances in order of decreasing energy content in kilocalories per gram: 1) proteins, 2) organic acids, 3) fats, 4) ethanol.
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What chemicals do peroxisomes use to oxidize other compounds? W) Mono-diglyceride X) Nitrogen dioxide Y) Hydrogen peroxide Z) Dihydrogen monoxide
W: W) Mono-diglyceride
X: X) Nitrogen dioxide
Y: Y) Hydrogen peroxide
Z: Z) Dihydrogen monoxide
Answer: Y) Y) Hydrogen peroxide
Name all of the following five insect orders that have adults with chewing mouthparts: 1) Hemiptera, 2) Strepsiptera, 3) Homoptera, 4) Lepidoptera, 5) Coleoptera.
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