Question | Answer | % Correct |
---|---|---|
What is the name of an object that absorbs all incoming radiation? | Black body | 80%
|
Electric | 80%
| |
The unit of measurement, hertz (Hz), was named after Heidrich Hertz and is the unit of measurement for: | Frequency | 80%
|
Maxwell concluded a mutual induction of what fields created self-propogating light waves? | Magnetic | 80%
|
In Hertz's experiment the spark in the receiver was induced by what newly found EM wave? | Radio waves | 80%
|
By explaining that quanta effectively collide with electrons when transferring energy, who helped Planck's theories be accepted? | Einstein | 60%
|
What does the photoelectric effect remove from a metal surface? | Electrons | 60%
|
According to classical physics, as energy in black bodies decreased, the intensity of the radiation emitted would approach what? | Infinity | 60%
|
If the frequency is below that point, no photoelectrons will be emitted even if what is very high? | Intensity | 60%
|
What is now the more common name for a 'packet' of energy rather than quantum? | Photon | 60%
|
Hertz also found that Radio waves had two other properties similar to light when he introduced a mirror. These properties were: | Reflection | 60%
|
Refraction | 60%
| |
The presence or absence of what was hotly debated in the 19th century to describe the propogation of light through space? | The Aether | 60%
|
As frequency in light waves increases, what increases for the electrons? | Their kinetic energy | 60%
|
Who said ^'s presence was irrelevant because it couldn't be detected and didn't effect the passage of light? | Albert Einstein | 40%
|
The amount of energy found in one 'packet' of quantised light was calculated witht the equation: | E=hf | 40%
|
What does the energy of the photoelectrons depend on? | Frequency | 40%
|
Who discovered the photoelectric effect accidentally? | Hertz | 40%
|
Hertz used what technique from Lloyd's mirror to calculate his own value for the speed of light | Interference | 40%
|
Maxwell's theory gave a defining connection between: | light and electricity | 40%
|
Name the device that converts energy from sunlight into electrical energy? | Photocell | 40%
|
What is the name for electrons emitted from a metal surface when a light source is shone on it? | Photoelectrons | 40%
|
In a graph plotting maximum kinetic energy against frequency in this experiment. What does the gradient represent? | Planck's constant | 40%
|
What does h represent in this equation | Planck's constant | 40%
|
Energy packets can be absorbed by atoms and then re-radiated. The idea of packets of quantised energy in light waves led to a new form of physics. What is this now known as? | Quantum Physics | 40%
|
What do solar cells use to harvest energy using the photoelectric effect? | Semiconductors | 40%
|
The peak in intensity of emitted energy from a black body rises and happens at lower wavelengths when what is increased? | Temperature of the black body | 40%
|
Philipp von Lenard, among other things, discovered a well-defined minimum voltage stopped the electrons from being emitted. What was this value called? | The Stopping Voltage | 40%
|
Radiation at a lower frequency then at a specific point will result in no emmision of photoelectrons. What is this frequency called? | The threshold frequency | 40%
|
^ violated the law of conservation of energy. What did physicists call this? | The Ultraviolet Catastrophe | 40%
|
What is the minimum energy required for the photoelectric effect to happen also known as? | The Work Function (W) | 40%
|
The photon has the nature that is sometimes like a wave and sometimes like a particle. What is this known as? | Wave-particle duality | 40%
|
What did Maxwell estimate as the speed of light (in m/s)? | 3.11x10^8 | 20%
|
What did Hertz use to produce sparks between spherical electrodes of a transmitter? | An induction coil | 20%
|
What equation calculates the maximum kinetic energy of a photoelectron? | Ek=hf-W | 20%
|
What does increasing the intensity of the light do? | Increases the number of emitted photoelectrons | 20%
|
What other characteristic of light did radio waves have? | Polarisation | 20%
|
To solve this, Planck proposed that energy could be exchanged between the radiation field and the particles in the black body. For this to work though, light must actually be what? | Quantised | 20%
|
All EM waves propogate at the speed of light | 0%
| |
Maxwell's two main predictions were: | light could exist with many different frequencies | 0%
|
What device is used in light gates and street lights that uses the photoelectric effect? | Photoconductive Cells | 0%
|
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