Physics — Conceptual (high school and intro college)

Les questions du quiz

1. 1. A 10-N force at an angle 45° above the horizontal has a horizontal component of about
   1. 7 N
   2. 5 N
   3. 10 N
   4. 12 N
2. 2. A completely submerged object always displaces its own
   1. weight of fluid.
   2. volume of fluid.
   3. density of fluid.
   4. All of these.
3. 3. When a diver points a flashlight upward toward the surface of the water at an angle 20° from the normal, the beam of light
   1. totally internally reflects
   2. passes into the air above
   3. is absorbed
   4. None of these
4. 4. According to four-dimensional geometry, the angles of a triangle add to 180°
   1. always.
   2. sometimes.
   3. never.
   4. on planet Earth only.
5. 5. A voltage will be induced in a wire loop when the magnetic field within that loop
   1. changes
   2. aligns with the electric field
   3. is at right angles to the electric field
   4. converts to magnetic energy
6. 6. Among these colors, the one that has the most energy per photon is
   1. red
   2. yellow-green
   3. blue
   4. violet
7. 7. According to general relativity,
   1. mass distorts spacetime.
   2. gravity affects clocks.
   3. light can’t escape from a black hole.
   4. All of these.
8. 8. A step-up transformer in an electric circuit can step up
   1. voltage
   2. energy
   3. Both of these
   4. Neither of these
9. 9. Spectral lines of the elements are
   1. chaotic
   2. ordered
   3. positioned by amplitude
   4. in phase
10. 10. A wave transfers
    1. amplitude
    2. wavelength
    3. frequency
    4. energy
11. 11. Immediately after two separated charged particles are released from rest, both increase in acceleration. The sign of charge of the particles is therefore
    1. the same
    2. opposite
    3. Either of these
    4. Need more information
12. 12. The surface of planet Earth loses energy to outer space due mostly to
    1. conduction
    2. convection
    3. radiation
    4. radioactivity
13. 13. In a series circuit, if the current in one lamp is 2 A, the current in the lamp next to it is
    1. half, 1 A
    2. 2 A
    3. Depends on which lamp is closer to the battery
    4. Not enough information to say
14. 14. As a blinking light source approaching you gains speed, you see the frequency of flashes
    1. increase.
    2. decrease.
    3. remain unchanged.
    4. None of these.
15. 15. In the absence of air resistance a ball of mass m is tossed upward to reach a height of 20 m. At the 10-m position half way up the net force on the ball is
    1. 2mg
    2. mg
    3. mg/2
    4. mg/4
16. 16. Pumice is a volcanic rock that floats in water. The density of pumice compared with that of water is
    1. less.
    2. equal.
    3. greater.
    4. none because it sinks.
17. 17. When you look at the red petals of a rose the color light you're seeing is
    1. red.
    2. green.
    3. white minus red.
    4. a mixture of green and yellow.
18. 18. 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?
    1. 0.005 C
    2. 0.01 C
    3. 0.02 C
    4. 0.5 C
19. 19. Which of these quantities decreases as the inverse square of distance for distances far from the objects producing the fields?
    1. the electric field produced by a finite-length charged rod
    2. the electric field produced by an infinitely long charged cylinder
    3. the electric field produced by an infinite plane of charge
    4. the magnetic field produced by an infinitely long, straight current-carrying wire
20. 20. A solid, metal object is isolated from other charges and has charge distributed on its surface. The charge distribution is not uniform. It may be correctly concluded that the
    1. electric field outside the object is zero
    2. the electric field outside the object is equal to the electric field inside the object
    3. the electric field outside the object is directly proportional to the distance away from the center of mass of the object
    4. the electric field outside the object, but very close to the surface, is equal to the surface charge density at any location divided by the permittivity of free space
21. 21. Standing waves are produced by a 100-Hz generator in a string of fixed length. The tension in the string is increased until a new set of standing waves is produced. Will the wavelength of the new standing waves be greater than or less than the wavelength of the original standing waves?
    1. Less, because the tension in the string varies directly with the wave speed, which varies inversely with the wavelength.
    2. Greater, because the tension in the string varies directly with the wave speed, which varies inversely with the wavelength.
    3. Greater, because the tension in the string varies directly with the wave speed, which varies directly with the wavelength.
    4. Less, because the tension in the string varies directly with the wave speed, which varies directly with the wavelength.
22. 22. Two identical capacitors are hooked in parallel to an external circuit. Which of the following quantities must be the same for both capacitors? I. the charge stored on the capacitor II. the voltage across the capacitor III. the capacitance of the capacitor
    1. I only
    2. II only
    3. II and III only
    4. (E) I, II, and III
23. 23. A 1-kg object is released from rest at the top of a rough-surfaced incline. The object slides without rotating to the bottom of the incline. The object’s kinetic energy at the bottom must be
    1. Equal to the block’s gravitational potential energy when it was released, because total mechanical energy must be conserved.
    2. Equal to the block’s gravitational potential energy when it was released, because the gain in kinetic energy compensates for the mechanical energy lost to thermal energy on the rough incline.
    3. Less than the block’s gravitational potential energy when it was released, because the gravitational potential energy was converted both to thermal energy and to kinetic energy.
    4. Less than the block’s gravitational potential energy when it was released, because the work done by the friction force must be greater than the block’s gain in kinetic energy.
24. 24. A student is experimenting with a simple spring-block oscillator of spring constant k and amplitude A. The block attached to the spring has a mass of m. If the student places a small block of mass m on top of the original block, which of the following is true?
    1. The small block is most likely to slide off when the original block is at maximum displacement from the equilibrium position, but will not slide off as long as the coefficient of static friction between the blocks is greater than kA/[(M+m)g].
    2. The small block is most likely to slide off when the original block is at the equilibrium position, but will not slide off as long as the coefficient of static friction between the blocks is greater than kA/[(M+m)g].
    3. The small block is most likely to slide off when the original block is at maximum displacement from the equilibrium position, but will not slide off as long as the coefficient of static friction between the blocks is greater than (M+m)g/(kA).
    4. The small block is most likely to slide off when the original block is at the equilibrium position, but will not slide off as long as the coefficient of static friction between the blocks is greater than (M+m)g/(kA).
25. 25. How much work is required to charge a 10 µF capacitor to a potential difference of 100 V ?
    1. 0.005 J
    2. 0.01 J
    3. 0.05 J
    4. 0.1 J
26. 26. A box of mass m slides on a horizontal surface with initial speed v0. It feels no forces other than gravity and the force from the surface. If the coefficient of kinetic friction between the box and the surface is μ, how far does the box slide before coming to rest?
    1. v0^2/(2μg)
    2. v0^2/(μg)
    3. 2v0^2/(μg)
    4. mv0^2/(μg)
27. 27. A soccer ball, at rest on the ground, is kicked with an initial velocity of 10 m/s at a launch angle of 30°. Calculate its total flight time, assuming that air resistance is negligible.
    1. 0.5 s
    2. 1 s
    3. 2 s
    4. 4 s
28. 28. Two identical containers are filled with different gases. Container 1 is filled with hydrogen and container 2 is filled with nitrogen. Each container is set on a lab table and allowed to come to thermal equilibrium with the room. Which of the following correctly compares the properties of the two gases?
    1. The average kinetic energy of the hydrogen gas is greater than the nitrogen gas.
    2. The average force exerted on the container by the hydrogen gas is greater than the nitrogen gas.
    3. The density of the hydrogen gas is less than the nitrogen gas.
    4. The pressures of the gases cannot be compared without knowing the number of molecules in each container.
29. 29. A girl of mass m and a boy of mass 2m are sitting on opposite sides of a see-saw with its fulcrum in the center. Right now, the boy and girl are equally far from the fulcrum, and it tilts in favor of the boy. Which of the following would NOT be a possible method to balance the see-saw?
    1. Move the boy to half his original distance from the fulcrum.
    2. Move the girl to double her original distance from the fulcrum.
    3. Allow a second girl of mass m to join the first.
    4. Move the fulcrum to half its original distance from the boy.
30. 30. When hot water is poured into a beaker containing cold alcohol, the temperature of the mixture will eventually reach the same temperature. Considering the scale of the size of the molecules of the fluids, which of the following is the primary reason for this phenomenon?
    1. The high temperature water will rise to the top of the container until it has cooled and then mixes with the alcohol.
    2. The molecules of the water continue to have a higher kinetic energy than the molecules of the alcohol, but the two liquids mix until the energy is spread evenly throughout the container.
    3. The hot water produces thermal radiation that is absorbed by the cold alcohol until the kinetic energy of all the molecules is the same.
    4. The water molecules collide with the alcohol molecules, transferring energy until the average kinetic energy of both the water and alcohol molecules are the same.

… et 15 autres questions.