Physics Trivia Questions for Students — page 8

A person standing on a horizontal floor is acted upon by two forces: the downward pull of gravity and the upward normal force of the floor. These two forces

• Ahave equal magnitudes and form an action-reaction pair
• Bhave unequal magnitudes and form an action-reaction pair
• Chave unequal magnitudes and do not form an action-reaction pair
• Dhave equal magnitudes and do not form an action-reaction pair

Which of the following changes to a double-slit interference experiment would increase the widths of the fringes in the interference pattern that appears on the screen?

• AUse light with a lower wave speed.
• BMove the slits closer together.
• CMove the screen closer to the slits.
• DUse light of a shorter wavelength.

Suppose the number of neutrons in a reactor that is starting up doubles each minute reaching one billion neutrons in 10 minutes. When did the number of neutrons reach half a billion?

• A9 minutes.
• B2 minutes.
• C5 minutes.
• D1 minute.

How much current does a 60 W light bulb draw if it operates at a voltage of 120 V ?

• A0.25 A
• B0.5 A
• C4:00 AM
• D2:00 AM

In both fission and fusion, energy is released while mass

• Aincreases
• Bmay decrease or increase
• Cdecreases
• Dremains unchanged; is conserved

Compared with radiation from the Sun, terrestrial radiation has a lower

• Afrequency
• BBoth
• Cwavelength
• DNeither

Which of these does NOT belong in the family of electromagnetic waves?

• ALight
• BSound
• CRadio waves
• DX-rays

If L, M, and T denote the dimensions of length, mass, and time, respectively, what are the dimensions of power?

• AM(L^2)/T^3
• B(L^2)M/T^3
• C(L^2)M/T^2
• D(M^2)L/T^2

Which configuration of battery and resistors will create a circuit with the greatest current?

• AA high voltage battery with resistors arranged in parallel
• BA high voltage battery with resistors arranged in series
• CA low voltage battery with resistors arranged in parallel
• DA low voltage battery with resistors arranged in series

For a tube closed at one end, the length of the tube at a frequency of 256 Hz will be

• Aone-half the value for a tube open at both ends
• Btwice the value for a tube open at both ends
• Cfour times the value for a tube open at both ends
• Done-quarter the value for a tube open at both ends

Clocks on a fast-moving spaceship whizzing past Earth appear to run slow when viewed from

• ABoth of these.
• BNeither of these.
• CEarth.
• Dinside the spaceship.

When a cannonball is fired from a cannon, both the cannonball and the cannon experience equal

• ABoth
• Baccelerations
• CNeither
• Damounts of force

The pressure at the bottom of a pond does NOT depend on the

• Adepth of the pond.
• Bacceleration due to gravity.
• Csurface area of the pond.
• Dwater density.

A string is plucked producing four loops (antinodes). The length of the string is 12.00 m. The wavelength of the wave must be

• A24.0 m
• B6.00 m
• C3.00 m
• D48.0 m

A principal source of the Earth's internal energy is

• Asolar radiation.
• Bgravitational pressure.
• Cradioactivity.
• Dtidal friction.

The phenomenon of beats results from sound

• AAll of these.
• Binterference.
• Creflection.
• Drefraction.

In his special theory of relativity, Einstein stated that the laws of physics are

• Adifferent in different situations.
• Bcommon sense applied to microscopic and macroscopic things.
• Cthe same in all uniformly moving frames of reference.
• Dthe same in all frames of reference.

Compared with the current in an LED lamp the current in the connecting wire is

• Amore.
• BNeed more information.
• Cthe same.
• Dless.

When you bend the branch of a tree by hanging on its end, the top side of the branch is under

• ABoth.
• Btension.
• CNeither.
• Dcompression.

The pitch of a sound is mostly related to its

• Aintensity
• Bspeed
• Cfrequency
• Damplitude

Heat is added to a cylindrical aluminum rod of radius Q and length ℓ. The temperature difference between the two ends of the rod varies from 10°C to 20°C. What geometric factors will influence the rate heat is transferred along the rod?

• ANeither the length nor area
• BBoth the length and area
• COnly the length
• DOnly the area of the rod

The greenhouse gases that contribute to global warming are

• ABoth
• Bcarbon dioxide
• Cwater vapor
• DNeither

The amount of air drag on an 0.8-N flying squirrel dropping vertically at terminal velocity is

• A0.8 N
• Bdependent on the orientation of its body
• Cless than 0.8 N
• Dgreater than 0.8 N

How many electrons are there in the third shell of sodium, Na (atomic number 11)?

• ANone
• BTwo
• COne
• DThree

An arrow is aimed horizontally, directly at the center of a target 20 m away. The arrow hits 0.050 m below the center of the target. Neglecting air resistance, what was the initial speed of the arrow?

• A100 m/s
• B40 m/s
• C20 m/s
• D200 m/s

Most of the radiation in Earth's biosphere is

• Anatural background radiation
• Bfrom nuclear power plants
• Cthe result of military activities
• Din the form of cosmic rays

It is observed that sounds can be heard around a corner but that light cannot be seen around a corner. What is a reasonable explanation for this observation?

• ALight travels at 3 × 10^8 m/s, which is too fast to change direction around a corner.
• BLight is an electromagnetic wave that is behaving as a particle.
• CSound has a longer wavelength, which increases the diffraction.
• DSound is a mechanical wave that can change direction in its propagation media.

A point charge, Q = +1 mC, is fixed at the origin. How much work is required to move a charge, Q = +8 µC, from the point (0, 4 meters) to the point (3 meters, 0)?

• A40 J
• B22.5 J
• C6.0 J
• D3.5 J

The position of an object is given by the equations x = 2.0t^3 + 4.0t + 6.25, where x is in meters and t is in seconds. What is the acceleration of the object at t = 1.50 s?

• A24 m/s^2
• B12 m/s^2
• C6 m/s^2
• D18 m/s^2

When food is exposed to gamma radiation, the food

• Ashould be avoided
• Bdoesn't become radioactive
• Cbecomes slightly radioactive
• Dwill spoil faster

If you were to travel at a speed close to the speed of light, you could notice that your own

• Apulse decreases.
• BBoth of these.
• Cmass changes.
• DNeither of these.

In the laboratory, a cart experiences a single horizontal force as it moves horizontally in a straight line. Of the following data collected about this experiment, which is sufficient to determine the work done on the cart by the horizontal force?

• AThe magnitude of the force, the cart's initial speed, and the cart's final speed
• BThe mass of the cart and the distance the cart moved
• CThe mass of the cart, the cart's initial speed, and the cart's final speed
• DThe mass of the cart and the magnitude of the force

The radius of Mars is about half that of Earth; the mass of Mars is about one-tenth that of Earth. Which of the following is closest to the gravitational field at the surface of Mars?

• A4 N/kg
• B0.5 N/kg
• C2 N/kg
• D10 N/kg

When a ball at rest hangs by a single vertical string tension in the string is mg. If the ball is made to move in amhorizontal circle so that the string describes a cone string tension

• Ais greater than mg always
• Bmay be greater or less than mg depending on the speed of the ball
• Cis less than mg always
• Dis mg

A solid plastic cube with uniform density (side length = 0.5 m) of mass 100 kg is placed in a vat of fluid whose density is 1200 kg/m^3. What fraction of the cube's volume floats above the surface of the fluid?

• A1.0/9
• B1.0/3
• C4.0/5
• D2.0/3

As entropy in a system increases, energy in the system

• Abecomes more ordered
• Breaches equilibrium
• Cbecomes less ordered
• Dmoves toward destruction

If the Sun were twice as massive, its pull on Mars would be

• Aunchanged
• Bfour times as much
• Ctwice as much
• Dhalf as much

Thermal conduction involves mainly

• Aprotons
• Belectrons
• Cions
• Dneutrons

An ideal fluid flows through a pipe with radius Q and flow speed V. If the pipe splits up into three separate paths, each with radius (Q/2), what is the flow speed through each of the paths?

• A2/3 V
• B4/3 V
• C1/3 V
• D4V

Which process would release energy from gold: fission or fusion? From carbon?

• AGold: fusion; carbon: fusion
• BGold: fusion; carbon: fission
• CGold: fission; carbon: fission
• DGold: fission; carbon: fusion

A pair of protective headphones reduces the sound of a jet engine from 140 dB to 110 dB. What percent of the noise is being blocked?

• A99.90%
• B78.60%
• C0.10%
• D21.40%

A common nuclear fission reactor

• Agets energy from nothing
• Bheats water
• Cgenerates electricity directly
• Dis a major polluter of the atmosphere

If the volume of an object were to double, with no change in mass, its density would

• Abe the same.
• Bhalve.
• Cdouble.
• DNone of these.

Under what conditions is the net electric flux through a closed surface proportional to the enclosed charge?

• Aonly when the enclosed charge is symmetrically distributed
• Bonly when there are no charges outside the surface
• Cunder any conditions
• Donly when all nearby charges are symmetrically distributed

In a mixture of hydrogen oxygen and nitrogen gases at a given temperature the molecules having the greatest average speed are those of

• Ahydrogen.
• Bnitrogen.
• CBut all have the same speed on average.
• Doxygen.

Experimenter A uses a very small test charge qo, and experimenter B uses a test charge 2qo to measure an electric field produced by two parallel plates. A finds a field that is

• Aless than the field found by B
• Bthe same as the field found by B
• Ceither greater or less than the field found by B, depending on the accelerations of the test charges
• Dgreater than the field found by B

Which of these three elements has the most mass per nucleon?

• AHydrogen
• BIron
• CSame in each
• DUranium

The definition of magnetic inclination is the angle between

• Athe earth's magnetic field at any point and the horizontal
• Bthe earth's magnetic field at any point and the vertical
• Cmagnetic north and geographic south
• Dmagnetic north and geographic north

You have a wire of length L, radius Q, and resistance Q. You need to obtain half that resistance using the same material and changing only one factor. You could

• Ause twice the radius
• Buse half the length
• Cuse half the radius
• Duse twice the length

The plates of a capacitor are charged to a potential difference of 5 V. If the capacitance is 2 mF, what is the charge on the positive plate?

• A0.5 C
• B0.005 C
• C0.02 C
• D0.01 C