Copper 390 380 Silver 230 Platinum 130 Five metal samples, with equal masses, are heated to 200oC. Each solid is dropped into a beaker containing 200 ml 15oC water. Which metal will cool the fastest? A) aluminum B) copper C) gold D) platinum E) None of the Explanation: The correct answer is platinum. Specific heat is the measure of the heat energy required to increase or decrease the temperature of a substance by a certain temperature interval. Platinum has the lowest specific heat; that means it takes less energy to lower or raise the temperature of platinum compared to the other four solids. 30) Conduction occurs more easily between solids and liquids. This is because the particles in are A) further and move faster. B) closer together and move faster. C) further and move more slowly. D) closer together and move more slowly. E) None of the above Explanation: Gases do not transfer heat as easily through conduction because their particles are further apart and move faster. Close proximity of molecules in a substance helps facilitate the transfer of heat. Quiz Standard 8 Answer Key Teacher Name: Quiz Generated On: 04-29-2016 1) Barbie sits on one end of a see-saw and Ken sits on the Barbie goes up in the air and Ken stays down on the ground. In order for Ken to make Barbie move down, he should A) stand on the board.
B) The box's velocity will be 1 m/s. C) The box's velocity will not change. D) The box will experience acceleration. E) None of the above Explanation: The correct answer is The box will experience acceleration. The box experiences unbalanced forces and will, therefore, accelerate. We don't have enough information to know whether the box will slow down or up or to know know how fast the box will travel. Quiz Standard 9 Answer Key Teacher Name: Quiz Generated On: 04-29-2016 1) AM Radio Waves Ultraviolet Light X Rays Visible Light What is true for ALL of the examples of electromagnetic waves? A) They all move at the same speed in a vacuum. B) They all have the same wavelength. C) They all have the same frequency. D) They all have the same energy. E) None of the above Explanation: All of these types of electromagnetic radiation travel the same speed. They are all forms of light, and travel at the speed of light. 2) Sound waves travel fastest through A) air. B) steel. C) water. D) a vacuum. E) None of the above
E) None of the Explanation: As the source moves away, the sound waves stretches out relative to the person standing still; so the pitch drops. Even though the sound waves are being emitted at the same frequency, the distance is not constant; so as the object gets farther and farther away, there appears to be more time between waves to the individual standing still; so the pitch, or frequency, lowers. 20) What type of waves move energy forward, but the source moves up and down? A) medium waves B) particle waves C) transverse D) longitudinal waves E) None of the Explanation: The correct answer is transverse waves. Longitudinal waves move the energy forward and the source also moves parallel to the energy. The other two are made up waves. 21) Light waves A) do not require a medium. B) can not travel in a vacuum. C) are not electromagnetic radiation. D) do not travel in straight lines from the source. E) None of the above Explanation: Light waves do not require a medium. Light waves are electromagnetic radiation and do not require a medium so they can travel through a medium. 22) Why does light refract when it encounters the glass in a lens? A) because it speeds up, causes it to bend B) because it slows down, which causes it to bend C) because it hits a dense medium, which causes it to bounce off D) because it gets absorbed, causes it to lessen in intensity E) None of the above
Explanation: hits the glass in a lens because it slows down, which causes it to bend. The material of a lens is more optically dense than the air it is traveling from. 23) In what way are all waves and light waves similar? A) They both transmit energy. B) They both require a medium for transmission. C) Neither of them require a medium for transmission. D) They both transmit matter without transmitting energy. E) None of the above Explanation: Both sound and light waves transmit energy. All waves are a disturbance that move through space and time transferring energy. 24) All waves carry A) energy. B) light. C) matter. D) particles. E) None of the above Explanation: All waves carry energy. Waves are a disturbance that moves through space and time transferring energy. 25) Visible represents a very small portion of the electromagnetic spectrum. Radiation to the left in the image, such as microwaves, has a longer wavelength than visible light. Radiation to the right has a shorter wavelength than is observable. Which radiation has a higher frequency than visible light? A) B) Infrared C) microwave radiation D) the frequency of all radiation is the same E) None of the Explanation:
C) parallel D) series E) None of the above Explanation: The statements all describe a series circuit. 11) The voltage in each path is the same. There is more than one path for electrons to reach resistors. The total current in a circuit will increase when a path is added. These statements are all true for ___________ circuits. A) closed B) open C) parallel D) series E) None of the Explanation: These statements are true for parallel circuits. 12) Why might an electromagnet be used to pick up old cars in junk yards? A) Electromagnets are inexpensive and easily create revenue. B) Electromagnets are powerful and can be turned on and off easily. C) Electromagnets are easy to operate and can be run by cheap labor. D) Electromagnets are versatile and can pick up any metallic objects in the yard. E) None of the above Explanation: Electromagnets are powerful and can be turned on and off easily. They are quite expensive and only pick up cars of iron or steel. 13) All of the following use an electric motor, EXCEPT A) radio. B) blender. C) hair dryer. D) electric fan.
23) One advantage to this form of circuit is that A) voltage available to each light remains constant regardless of the number of lights that are on. B) current drawn from the battery remains constant regardless of the number of lights that are on. C) resistance along the circuit remains constant regardless of the number of lights that are on. D) current drawn from the battery decreases as more lights are turned on. E) None of the above Explanation: Unlike a series circuit, this type of circuit allows current and resistance to act independently for each loop so that voltage available to each light remains constant regardless of the number of lights that are on. 24) Turning a magnet very quickly would be BEST used to create A) radiation. B) waves. C) an electric current. D) a convection current. E) None of the Explanation: The reason that electric motors have magnets inside them is because they are essentially generators in reverse. They use electricity to turn a magnet, which then produces useful motion. A turning magnet will produce an electric current if placed near wires. 25) Which graph BEST represents the relationship between the electric current and the rate at which a magnet is turning inside an electric generator? A) B) C) D) E) None of the above Explanation: As an electrical generator spins faster, it creates more current as is shown by graph B. 26) During induction, a positively charged rod is brought near to but not touching the electroscope. The presence of the charged object above the plate of the electroscope induces charges to move down into the gold leaves, giving the
Explanation: The best material to use for the core of a electromagnet is iron. Iron, nickel, cobalt and some of the rare earths metals exhibit a unique magnetic behavior which is called ferromagnetism, or the ability to hold a magnetic field. 29) What is produced by moving a permanent magnet through a coil of copper wire? A) electricity B) electromagnet C) light D) radiation E) None of the above Explanation: Electricity is produced by turning a magnet through a coil of wire. This causes current to flow through the wire. This device is called a generator. 30) A strand of 10 lights is plugged into an outlet. How can you determine if the lights are connected in series or parallel? A) Unscrew one If the other lights stay on, it's a series circuit. B) Unplug the strand. If the first light stays on, it's a series circuit. C) Unscrew one light. If the other lights turn off, it's a series circuit. D) Cut the strand in half. If the plugged in half on, it's a series circuit. E) None of the above Explanation: The correct answer is Unscrew one light. If the other lights turn off, it's a series circuit. Series circuits only provide one path for the flow of electricity. Removing a light removes that path.