Quiz on Physics 1B

Which one statement is true about a thermogram?
1. It is heat sent a long way.
2. It is a term used for the heating bill of a large factory.
3. It is a picture made by a camera that detects infra red radiation
4. It is a picture made by a camera that detects ultra violet radiation
Microwaves have a wavelength of about
1. 1 micrometre (1 millionth of a metre)
2. 1 cm
3. 1 m
4. 1 km
Which one of these statements is NOT true for an electromagnetic wave?
1. It cannot travel through a vacuum.
2. It travels at 300 000 000 m/s
3. It travels in straight lines.
4. It is a transverse wave
Which one of these is true for a sound wave?
1. Sound waves travel at 3000 m/s in air
2. Sound waves pass easily through a vacuum.
3. Sound waves are transverse.
4. Sound waves are longitudinal.
Which one of these lists shows the correct order of the electromagnetic spectrum, going from long wavelength to short?
1. Microwaves, radio waves, ultra violet, infra red, visible, X-rays, gamma rays
2. Radio waves, microwaves, visble light, ultra violet, infra red, X-rays, gamma rays.
3. Radio waves, microwaves, infra red, visible light, ultra violet, X-rays, Gamma rays.
4. Gamma rays, X-rays, ultra violet, visible light, infra red, microwaves, radio waves
The wave equation is:
1. speed = frequency × wavelength
2. speed = frequency ÷ wavelength
3. speed = frequency + wavelength
4. speed = frequency - wavelength
Whihc one of these absorbs electromagnetic waves best?
1. A glossy black surface
2. A dull black surface
3. A glossy white surface.
4. A dull white surface.
Which one of these is used on a sun-bed to give an artificial tan?
1. Microwaves
2. Infra red
3. Ultra violet
4. Gamma rays.
Optical fibres work by TIR. This stands for:
1. Total internal refraction
2. Total internal reflection
3. Total internal reaction
4. Total internal retribution
In refraction, when a ray goes from air to glass at an angle of incidence, which one of these happens?
1. The ray is absorbed.
2. All the ray is reflected off the surface.
3. The angle of incidence is greater than the angle of refraction.
4. The angle of incidence is less than the angle of refraction.
In perspex, the critical angle is 43 degrees. This means that:
1. at any angle above 43 degrees, the angle of refraction starts to decrease instead of increase.
2. there is a risk of the block starting to melt and possibly catch fire.
3. the ray is absorbed and disappears.
4. total interanal reflection occurs.
Carbon-14 has a mass number of 14 and an atomic number of 6. Which one of these statements is true?
1. There are 6 neutrons and 14 protons in the nucleus.
2. There are 6 protons and 8 neutrons in the nucleus.
3. There are 8 protons and 6 neutrons in the nucleus.
4. There are 14 neutrons and 6 protons in the nucleus.
An isotope of an element contains:
1. the same number of protons, but different numbers of neutrons.
2. the same number of neutrons but different numbers of protons.
3. the same number of protons, but different numbers of electrons.
4. a third particle in the nucleus called a moron.
Nuclear fission is caused by:
1. radioactive decay.
2. the atom gaining too many electrons
3. a neutron neing absorbed into an unstable nucleus, causing it to fall apart.
4. exposure to gamma rays.
Which one of these statements is correct about radioactive decay by alpha radiation?
1. The radiation needs several centimetres of lead to stop it.
2. The particle is a helium nucleus.
3. The particle is a helium atom.
4. Alpha particles are in themselves very radioactive.
Radioactive decay particles are described as ionising. Which one of these statements is correct?
1. Alpha particles are only weakly ionising because they are absorbed by paper.
2. Gamma rays are very ionising because they penetrate several centimetres of lead.
3. Beta particles and gamma rays carry an electrical charge.
4. The particles knock electrons off atoms they collide with.
After 1 half life, 50 % of the original atoms remain. After 2 half-lives, the number of atoms remaining is:
1. 25 %
2. 12.5 %
3. 6.25 %
4. Zero. All the atoms have died.
By which one of these processes can you alter the half life of a radioactive isotope?
1. Reacting it with a strong acid.
2. Heating it to a very high temperature.
3. Subjecting it to very high pressures.
4. None of these. The half life cannot be altered.
For which one of the applications below would you use an alpha emitter?
1. Medical tracer.
2. To llok for flaws (hidden holes) in a metal casting.
3. Smoke detector.
4. Controlling thickness of sheet materials.
Astronomers on the ground may have difficulty using their telescopes to get clear images. Which one of these is the best way of getting the clearest images?
1. Waiting for a cold frosty night.
2. Putting the telescope into orbit.
3. Taking it up in an aeroplane
4. Putting it on a high mountain.
Cosmonauts in orbit around the Earth always experience weightlessness. This is because:
1. the centrifugal force on the orbit acts in the opposite direction to gravity and cancels it out.
2. the cosmonauts are falling towards the earth under the pull of gravity, and the space ship is falling at the same rate.
3. there is no gravity.
4. the centrifugal force cancels out the magnetism of the Earth.
Stars are formed by:
1. the pull of gravity.
2. electrical attraction by oppositely charged ions.
3. magnetism
4. chemical reacts between dust and gas particles.
The time taken for a star to form is:
1. a fraction of a second.
2. Several days
3. A few months
4. Millions of years.
New stars do not light immediately, although they form a glowing ball. At this stage they are called.
1. Novas
2. Protostars
3. Nebulae
4. Yellow dwarfs.
The Solar System formed from:
1. a star that collided with the Sun
2. rocks that were caught by the gravity of the sun.
3. debris thrown out by the explosion that happened when the sun lit.
4. a disc of dust and gas that was rotating and swirling about the forming sun
Magnetic storms on the sun can cause a nuisance. Which one of these is a nuisance caused by magnetic storms?
1. Northern lights
2. Disruption to telecommunications
3. Thunderstorms
4. Volcanic activity
At the end of its life, a star like our sun ends up as a black dwarf. A star that is ten times bigger will end up as:
1. a big planet
2. a brown dwarf
3. a white dwarf
4. a black hole.
Which one of these theories is accepted by most scientists about the start of the Universe?
1. It never started at all; it has always been the way it is now.
2. There was a titanic explosion from which all materials were formed.
3. The universe evolved from previous more primitive universes.
4. None of these.
Scientists say that the universe is expanding. How do they know?
1. Red shift shows that galaxies are moving away.
2. Blue shift shows that galaxies are moving away.
3. The universe is middle aged and getting middle-aged spread.
4. The population of the universe is getting bigger all the time.
Which is the statement that scientists believe about the end of the universe?
1. It will happen in about fifty years time.
2. It will never happen, since the universe is infinite. It never started, nor will it end.
3. There are a number of theories that depend on how much dark matter there is.
4. It will collapse because there will be too many worm-holes in the space-time continuum, weakening the structure.