HS Sample Set 2, Round 12 from NSB
A 9 volt battery is connected to a 9 Ω resistor. The current flowing through this circuit is found to be 0.9 A. Neglecting the resistance of the wires, what is the internal resistance of the battery in ohms?
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The root mean square current of an alternating current is equal to the direct current that does which of the following? W) Dissipates an equal amount of power in a resistor as the peak power dissipated by the alternating current X) Dissipates an equal amount of power in a resistor as the average power dissipated by the alternating current Y) Produces the same average voltage across a resistor as the alternating current would Z) Provides the same average current in a resistor as the alternating current would
W: W) Dissipates an equal amount of power in a resistor as the peak power dissipated by the alternating current
X: X) Dissipates an equal amount of power in a resistor as the average power dissipated by the alternating current
Y: Y) Produces the same average voltage across a resistor as the alternating current would
Z: Z) Provides the same average current in a resistor as the alternating current would
Answer: X) X) Dissipates an equal amount of power in a resistor as the average power dissipated by the alternating current
Roof overhangs used to shade windows, walls, and doors from direct solar radiation in order to cut down on cooling costs are an example of what kind of home energy design?
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In megawatts, to the nearest tenth, how much power is generated from a hydroelectric facility that has a head of 50 m, a flow rate of 5,000 L/s, and a coefficient of efficiency of 0.6?
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Dinitrogen tetroxide decomposes according to the reaction: N₂O₄(g) ⇌ 2 NO₂(g). If nitrogen dioxide appears at a rate of 4 M/s, at what rate in M/s is the dinitrogen tetroxide disappearing?
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Which of the following is the most sensitive type of polarography? W) Normal pulse X) Classical Y) Differential pulse Z) Current-sampled
W: W) Normal pulse
X: X) Classical
Y: Y) Differential pulse
Z: Z) Current-sampled
Answer: Y) Y) Differential pulse
Evaluate $\displaystyle \lim_{x\to 0}\frac{-5+5e^x}{x}$. $$\displaystyle \lim_{x\to0}\frac{-5+5e^x}{x}$$
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Determine the quadratic equation with real coefficients and least integral leading coefficient that has $3 - 2i$ as one root.
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Which physical property of soil involves the concepts of matric potential and field capacity?
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Why are massive compact halo objects (MACHOs) thought to be unable to completely explain the dark matter problem? W) They would have evaporated by Hawking radiation in less than a Hubble time X) Cosmic microwave background radiation observations indicate that MACHOs could not have formed in a Hubble time Y) Several MACHOs would be detectable in the solar system but are not observed Z) There should be a lot more MACHOs observed through microlensing
W: W) They would have evaporated by Hawking radiation in less than a Hubble time
X: X) Cosmic microwave background radiation observations indicate that MACHOs could not have formed in a Hubble time
Y: Y) Several MACHOs would be detectable in the solar system but are not observed
Z: Z) There should be a lot more MACHOs observed through microlensing
Answer: Z) Z) There should be a lot more MACHOs observed through microlensing
During electron transport chains in both photosynthesis and cellular respiration, the electron transport chain directly transfers energy from electrons to which of the following? W) ATP X) ATP synthase Y) The proton gradient Z) NADH or NADPH
W: W) ATP
X: X) ATP synthase
Y: Y) The proton gradient
Z: Z) NADH or NADPH
Answer: Y) Y) The proton gradient
When under heat stress, pelicans perform a specific type of panting behavior. What is this heat-induced behavior called?
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Which of the following scientists made the theoretical prediction that electromagnetic waves travel through a vacuum at the speed of light? W) James Clark Maxwell X) Michael Faraday Y) Heinrich Lenz Z) Heinrich Hertz
W: W) James Clark Maxwell
X: X) Michael Faraday
Y: Y) Heinrich Lenz
Z: Z) Heinrich Hertz
Answer: W) W) James Clark Maxwell
During the season when the Northern Hemisphere experiences winter, the Earth is located closest to the Sun. Which of the following effects does this have on the Earth’s revolution speed? W) The Earth revolves faster around the Sun at this point X) The Earth revolves slower around the Sun at this point Y) The speed of revolution at this point is proportional to the cube of the Earth-Sun distance Z) The speed of Earth’s revolution is always constant
W: W) The Earth revolves faster around the Sun at this point
X: X) The Earth revolves slower around the Sun at this point
Y: Y) The speed of revolution at this point is proportional to the cube of the Earth-Sun distance
Z: Z) The speed of Earth’s revolution is always constant
Answer: W) W) The Earth revolves faster around the Sun at this point
Given that the half-life of uranium-235 is 700 million years, if you had 160 g of U-235, how many grams would remain after 2.1 billion years?
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Sodium crystallizes in the form of a body-centered cubic unit cell. If one atom of sodium has a radius of 180 pm, what is the length, in picometers, of one side of the unit cell? W) 255 X) 360 Y) 416 Z) 509
W: W) 255
X: X) 360
Y: Y) 416
Z: Z) 509
Answer: Y) Y) 416
What is the equation of the circle with a diameter that has endpoints $(-5,\,12)$ and $(5,\,-12)$?
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Evaluate $\displaystyle \int_{-1}^{1}(x^3 + 1)\,dx$.
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What is the term for a highly magnetized neutron star?
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Defining the density of a black hole to be its mass divided by the cube of its Schwarzschild radius, what is the density of a typical supermassive black hole, in g/cm³, to within two orders of magnitude?
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What is the specific name of the chemical compound found in jellyfish and squid that is oxidized to cause bioluminescence?
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Sperm whales have a specialized organ that is filled with oil that becomes solid at a relatively high temperature. Which of the following kinds of fatty acid would you predict to be found in the spermaceti organ? W) Trans X) Saturated Y) Polyunsaturated Z) Unsaturated
W: W) Trans
X: X) Saturated
Y: Y) Polyunsaturated
Z: Z) Unsaturated
Answer: X) X) Saturated
Kinetic-molecular theory makes several assumptions concerning ideal gases. Which of the following is NOT one of those assumptions? W) The average kinetic energy of the molecules is independent of temperature X) There are no attractive or repulsive forces between molecules Y) All collisions between molecules are elastic Z) The volume occupied by the gas molecules is negligible compared to the volume of the container
W: W) The average kinetic energy of the molecules is independent of temperature
X: X) There are no attractive or repulsive forces between molecules
Y: Y) All collisions between molecules are elastic
Z: Z) The volume occupied by the gas molecules is negligible compared to the volume of the container
Answer: W) W) The average kinetic energy of the molecules is independent of temperature
Water can frequently be employed in the self-assembly of nanoparticles by taking advantage of its surface properties. However, a particular self-assembly needs to take place in oil. Which of the following assembly processes would take advantage of the properties of the oil to make assembly possible? W) Electrostatic X) Magnetic Y) Hydrophobic Z) Capillary
W: W) Electrostatic
X: X) Magnetic
Y: Y) Hydrophobic
Z: Z) Capillary
Answer: W) W) Electrostatic
If you drop an ice cube into a mixture of alcohol and water and you notice that the ice floats, which of the following can you conclude about the liquid? W) The liquid is mostly water X) The liquid is mostly alcohol Y) Nothing, because information on the temperature of the liquid is not given Z) The liquid contains exactly equal amounts of water and alcohol
W: W) The liquid is mostly water
X: X) The liquid is mostly alcohol
Y: Y) Nothing, because information on the temperature of the liquid is not given
Z: Z) The liquid contains exactly equal amounts of water and alcohol
Answer: W) W) The liquid is mostly water
The Rayleigh criterion defines a limit on which of the following? W) Resolution in an optical system X) Particle velocity in an inelastic collision Y) Sustainable pressure for a given material Z) Shear stress for a given material
W: W) Resolution in an optical system
X: X) Particle velocity in an inelastic collision
Y: Y) Sustainable pressure for a given material
Z: Z) Shear stress for a given material
Answer: W) W) Resolution in an optical system
If a utility uses a true real time pricing rate structure, a residential customer could reduce consumption during the times of peak demand by upgrading all but which of the following? W) Lighting X) Heating Y) Air conditioning Z) Water heating
W: W) Lighting
X: X) Heating
Y: Y) Air conditioning
Z: Z) Water heating
Answer: W) W) Lighting
What process is represented by the following reaction? Coal + O₂ + H₂O → H₂ + CO
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What is the molecular geometry of the coordination compound \([Co(NH_3)_4Cl_2]^+\)?
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Match the following reactions—E2; SN2; E1—to the solvents in which they generally occur: 1) polar aprotic; 2) polar protic; 3) a variety of solvents.
Choices:
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Peano’s Axioms underlie which of the following mathematical concepts? W) Non Euclidean geometry X) Group theory Y) Natural numbers Z) Complex numbers
W: W) Non Euclidean geometry
X: X) Group theory
Y: Y) Natural numbers
Z: Z) Complex numbers
Answer: Y) Y) Natural numbers
What is the exact value of \(\cos 75^\circ\) in simplest radical form?
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How does the angle of repose change as an alluvial fan increases in size over time? W) It increases because the sediment increases in cohesion over time X) It increases to a maximum of 15 degrees Y) It remains the same Z) It is highly variable due to the nature of the sediments
W: W) It increases because the sediment increases in cohesion over time
X: X) It increases to a maximum of 15 degrees
Y: Y) It remains the same
Z: Z) It is highly variable due to the nature of the sediments
Answer: Y) Y) It remains the same
A disadvantage of an altazimuth mount compared to an equatorial mount is which of the following? W) It is more complicated to track stars as they move across the sky X) The telescope cannot observe the north celestial pole Y) It is more complicated to construct than an equatorial mount Z) It requires a larger dome
W: W) It is more complicated to track stars as they move across the sky
X: X) The telescope cannot observe the north celestial pole
Y: Y) It is more complicated to construct than an equatorial mount
Z: Z) It requires a larger dome
Answer: W) W) It is more complicated to track stars as they move across the sky
Which of the following pairs correctly matches the cellular structure or organelle with its function? W) Nucleolus and rRNA synthesis X) Smooth endoplasmic reticulum and carbohydrate synthesis Y) Centriole and transport of vesicles Z) Golgi apparatus and protein synthesis
W: W) Nucleolus and rRNA synthesis
X: X) Smooth endoplasmic reticulum and carbohydrate synthesis
Y: Y) Centriole and transport of vesicles
Z: Z) Golgi apparatus and protein synthesis
Answer: W) W) Nucleolus and rRNA synthesis
African, Egyptian, Caucasian, and Carniolan are all races of which of the following colonizing insects? W) Termites X) Bees Y) Ants Z) Grasshoppers
W: W) Termites
X: X) Bees
Y: Y) Ants
Z: Z) Grasshoppers
Answer: X) X) Bees
How many electrons are required to make up a net negative charge of 1 C? W) 1.6 × 10⁻¹⁹ X) 6.2 × 10¹⁸ Y) 1.6 × 10¹⁹ Z) 6.2 × 10¹⁹
W: W) 1.6 × 10⁻¹⁹
X: X) 6.2 × 10¹⁸
Y: Y) 1.6 × 10¹⁹
Z: Z) 6.2 × 10¹⁹
Answer: X) X) 6.2 × 10¹⁸
A pendulum attached to the ceiling has mass \(m\) and length \(L\), and is held at rest at an angle \(\theta\) with respect to the vertical. If released, which of the following is the kinetic energy at the lowest point? W) \(mgL\sin\theta\) X) \(mgL(1 - \sin\theta)\) Y) \(mgL\cos\theta\) Z) \(mgL(1 - \cos\theta)\)
W: W) \(mgL\sin\theta\)
X: X) \(mgL(1 - \sin\theta)\)
Y: Y) \(mgL\cos\theta\)
Z: Z) \(mgL(1 - \cos\theta)\)
Answer: Z) Z) \(mgL(1 - \cos\theta)\)
What is the name for the cooling process that employs water’s large enthalpy of vaporization?
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An argument escalates from 20 dB to 60 dB. By what factor is the peak-to-peak air pressure variation multiplied? W) 3 X) 100 Y) 1,000 Z) 10,000
W: W) 3
X: X) 100
Y: Y) 1,000
Z: Z) 10,000
Answer: X) X) 100
In the ocean, which of the following is the depth at which the rate of respiration of a photosynthetic organism is equal to its rate of photosynthesis? W) Compensation depth X) Critical depth Y) Oxygen minimum layer Z) Deep scattering layer
W: W) Compensation depth
X: X) Critical depth
Y: Y) Oxygen minimum layer
Z: Z) Deep scattering layer
Answer: W) W) Compensation depth
Which of the following correctly identifies the body of water in which you would find the vaquita, the most endangered cetacean? W) Northwest corner of the Gulf of California X) Throughout the Sea of Cortez Y) Southeast corner of the Sea of Cortez Z) Shallow lagoons off the coast of northern California
W: W) Northwest corner of the Gulf of California
X: X) Throughout the Sea of Cortez
Y: Y) Southeast corner of the Sea of Cortez
Z: Z) Shallow lagoons off the coast of northern California
Answer: W) W) Northwest corner of the Gulf of California
In the gas phase, one mole of H₂ reacts reversibly with one mole of I₂ to form two moles of HI. If the system is at equilibrium at constant temperature, how will equilibrium shift if the volume of the reaction vessel is doubled? W) It will shift toward the reactants X) It will shift toward the products Y) It will not shift in either direction Z) It is not possible to determine shift direction
W: W) It will shift toward the reactants
X: X) It will shift toward the products
Y: Y) It will not shift in either direction
Z: Z) It is not possible to determine shift direction
Answer: Y) Y) It will not shift in either direction
Uridine monophosphate (UMP) is essential to pyrimidine nucleotide synthesis. What amino acid combines with a bicarbonate ion and two ATPs in the first step of de novo UMP synthesis?
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Maximize the area in square feet of a rectangular pen bounded by the side of a barn and 100 ft of fencing that forms the other three sides.
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For the arithmetic sequence \(a_n\) with \(a_1 = 5\) and \(a_3 = -3\), what is \(a_{98}\)?
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What is the defining characteristic for detection of Type I supernovae?
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Which of the following is a location where serpentinite often forms? W) Flanks of a volcano X) Accreted terranes Y) Sedimentary basins Z) Magma chambers
W: W) Flanks of a volcano
X: X) Accreted terranes
Y: Y) Sedimentary basins
Z: Z) Magma chambers
Answer: X) X) Accreted terranes
As a volcanically formed island begins to experience subsidence, you would see a temporal progression of reef types in which order? W) Fringing reef, barrier reef, atoll X) Atoll, fringing reef, barrier reef Y) Barrier reef, fringing reef, atoll Z) Fringing reef, atoll, barrier reef
W: W) Fringing reef, barrier reef, atoll
X: X) Atoll, fringing reef, barrier reef
Y: Y) Barrier reef, fringing reef, atoll
Z: Z) Fringing reef, atoll, barrier reef
Answer: W) W) Fringing reef, barrier reef, atoll
Ciguatera is an illness caused by eating fish that contain toxins produced by a tropical marine dinoflagellate. Which of the following fish would be the safest to eat to avoid ciguatera? W) Barracuda X) Grouper Y) Trevally Z) Halibut
W: W) Barracuda
X: X) Grouper
Y: Y) Trevally
Z: Z) Halibut
Answer: Z) Z) Halibut