100 Updated Physics Interview Questions Part-1
Q – 1 A truck travels 420 m. each tire on the truck has a diameter of 42 cm. if one revolution of a tire is equal to 2? times the radius of the tire (in meters), which of the following equations shows how many revolutions each tire makes as the distance is traveled?
Ans-
Q – 2 All elements with an atomic number greater than what number are unstable?
Ans- 83
Q – 3 What is the name of the device that is made by combining two basic types of solid state rectifiers allowing the device to both rectify and amplify a current?
Ans- transistor
Q – 4 A coil of wire that produces a magnetic field is typically called a:
Ans- solenoid
Q – 5 In radio transmission, what does the acronym AM stand for?
Ans- amplitude modulation
Q – 6 What law yields an equation that is used in determining crystal structure from interference patterns produced by monochromatic X-rays?
Ans- Bragg’s Law
Q – 7 A color made from the addition of two primary colors is called:
Ans- secondary color
Q – 8 Who determined that the square of a planets period is proportional to the cube of its average distance from the sun?
Ans- Kepler
Q – 9 What is the dramatic increase in amplitude called when the frequency of forced vibrations on a body matches the bodys natural vibration frequency?
Ans- resonance
Q – 10 Heat cannot pass from a cooler substance to a warmer substance without some other process being involved. This is an example of which law of thermodynamics?
Ans- the second law
Q – 11 Sound frequencies below 16 Hertz are usually referred to by scientists as:
Ans- infrasonic
Q – 12 This perceived force, that seems to want to throw a person off a merry-go-round, is often regarded by physicists as a fictitious force:
Ans- centrifugal force
Q – 13 According to the standard model of particle physics, what is the name for the three leptons that have no electric charge and little if any mass?
Ans- Neutrino
Q – 14 What is the term for the speed at which an object will overcome the gravitational attraction of the Earth?
Ans- escape velocity
Q – 15 For projectiles fired at identical speeds but various angles from the ground, neglecting air resistance and the curvature of the Earth, at what angle will the maximum horizontal distance be attained?
Ans- 45 degrees
Q – 16 For two objects separated by a distance d, if the mass of one of the objects is doubled, what will happen to the gravitational attraction between them?
Ans- it is doubled
Q – 17 If the distance separating two charges is doubled, the force between them decreases by what multiple factor?
Ans- 4
Q – 18 What secondary color of light is produced by mixing the primary colors of red and blue?
Ans- magenta
Q – 19 Assuming g = 9.8 m/sec2, what is the weight on Earth, in Newtons, of a 60 kilogram person?
Ans- 588 Newtons
Q – 20 This person established the one fluid theory of electricity and performed some of the first investigations into electrical grounding and insulation:
Ans- Ben Franklin
Q – 21 Considering the specific heat of aluminum is 0.21, iron is 0.10, and lead is 0.03, which metal will show the largest increase in temperature per calorie added to one gram of that metal?
Ans- lead
Q – 22 If blue light is combined with green light, what color of light is produced?
Ans- Cyan
Q – 23 PHYSICS Short Answer To two significant figures, what is the index of refraction of air?
Ans- 1.0
Q – 24 What is the name for the physical constant with a value of 6.62 X 10-27 erg seconds?
Ans- Planck’s Constant
Q – 25 How many femtometers are in a nanometer?
Ans- one million
Q – 26 What formula is most appropriate to compute the kinetic energy of a block of ice sliding down an inclined plane?
Ans- KE=½ mv2
Q – 27 By primarily using what simple machine did Galileo come to the conclusion on the existence of friction?
Ans- inclined plane
Q – 28 Laser is an acronym for what?
Ans- light amplification by stimulated emission of radiation
Q – 29 Which of the following is the emission source for microwaves in a typical microwave oven:
Ans-
1. small cyclotron
2. cadmium disk bombarded with a soft x-ray source
3. magnetron
4. laser lamp
Answer: C
Q – 30 The fundamental forces of nature are most correctly given as:
Ans-
1. gravitational, electromagnetic, strong interactive, weak interactive
2. chemical, mechanical, friction and atomic
3. gravitational, electromotive, magnetic, atomic
4. graviton, photon, lepton, hadron
Answer: A
Q – 31 Which of the following particles has not yet been observed but is generally theorized to exist:
Ans-
1. mesons
2. gluons
3. fermionic hadrons
4. gravitons
Answer: D
Q – 32 What large machine, which came on line in the summer of 2000 at the Department of Energys Brookhaven National Lab, is the world’s highest energy ion collider:
Ans-
1. Advanced Photon Source
2. CERN supercollider
3. Relativistic Heavy Ion Collider
4. Phoenix
Answer: C
Q – 33 Which of the following colors of light has the greatest angle of refraction in normal glass:
Ans-
1. yellow
2. green
3. violet
4. red
Answer: C
Q – 34 Which of the following is measured in Hertz?
Ans-
1. speed
2. frequency
3. wavelength
4. amplitude
Answer: B
Q – 35 When a person whirls a rock on the end of a string and maintains it in uniform circular motion, the force exerted on the rock is most accurately referred to as:
Ans-
1. centrifugal
2. centripetal
3. rotational
4. center fleeing
Answer: B
Q – 36 Scientists at Brookhaven National Laboratory invented the forerunner of the PET, which was subsequently found to be well- suited for wide use in institutions around the world for which of the following:
Ans-
1. metabolic studies and clinical tests
2. deep sea drilling
3. nuclear spallation
4. deep space studies
Answer: A
Q – 37 Which of the following units is a measure of potential difference:
Ans-
1. erg
2. ohm
3. joule
4. volt
Answer: D
Q – 38 Which of the following exhibits the least resistivity at 0°C:
Ans-
1. mercury
2. tungsten
3. gold
4. silver
Answer: D
Q – 39 ASTRONOMY Multiple Choice A parsec is equal to which of the following:
Ans-
1. 100 Astronomical Units
2. 3.26 light years
3. 100 light years
4. 140 million kilometers
Answer: B
Q – 40 How is the index of refraction computed:
Ans-
1. the speed of light in a vacuum is divided by the speed of light in the material
2. the speed of light in the material is divided by the speed of light in a vacuum
3. the speed of light in water is divided by the speed of light in a vacuum
4. the speed of light in a vacuum is divided by the speed of light in water
Answer: A
Q – 41 According to the standard model of particle physics, which of the following is a force-carrying particle:
Ans-
1. proton
2. neutron
3. quark
4. photon
Answer: D
Q – 42 What is the following statement most commonly known as:
Ans- “A body immersed in a fluid is supported by a force equal to the weight of the fluid it displaces.”
Q – 43 By passing current through a wire wrapped around an iron rod, William Sturgeon invented the:
Ans- Electromagnet
Q – 44 If F equals electric force, and q and q (read as: q-prime) are the charges on two particles, the expression F is proportional to q times q prime divided by distance squared is what law?
Ans- Coulomb’s Law
Q – 45 What cycle most directly describes the working cycle of a heat engine operating as an ideal engine of maximum thermal efficiency?
Ans- Carnot Cycle
Q – 46 On an electric schematic, what does the symbol of a horizontal line interrupted by a saw tooth shaped line represent?
Ans- resistor
Q – 47 Order the following categories of electromagnetic radiation from the LOWEST frequency to the HIGHEST:
Ans- FM radio, UHF TV, AM radio, microwaves
Q – 48 Which element has the simplest absorption spectrum?
Ans- Hydrogens
Q – 49 How many neutrons and how many protons are present in a single deuterium nucleus?
Ans- one proton and one neutron
Q – 50 The throbbing caused by sounds of slightly different frequencies that results because of periodic constructive and destructive interference is called:
Ans- beats
Q – 51 Assuming friction is negligible, if a lever has a mechanical advantage of 5, how much effort in newtons is needed to lift a 10 newton load?
Ans- 2 Newtons
Q – 52 While at Berkeley, Melvin Calvin used this radioisotope to decipher many of the complex processes of photosynthesis:
Ans- Carbon 14
Q – 53 What is the general term for the kind of material usually placed between the conducting plates of a capacitor?
Ans- Dielectric
Q – 54 How many more times louder is 70 decibels than 10 decibels?
Ans- One Million
Q – 55 When a green colored object is illuminated by a green light it will appear as what color to the human eye?
Ans- Green
Q – 56 When Thomas Edison was promoting the wide use of direct current, this personal enemy of Edisons was the chief proponent and expert in alternating current:
Ans- Nikola Tesla
Q – 57 In the 19th century, this Scottish scientist showed that all magnetic and all electric phenomena could be described by four equations that often bear his name. What is his name?
Ans- James Clerk Maxwell
Q – 58 A bullet of mass m travelling at velocity v has a kinetic energy of ½mv2 when it strikes a ballistic pendulum of mass 1000 grams. The kinetic energy of the two masses moving together just after the moment of impact is about a thousand times smaller than ½mv2. What has most of the bullets initial kinetic energy been converted to?
Ans- heat
Q – 59 Order the following from the WORST electrical conductor to the BEST electrical conductor: glass, rubber, iron, dry wood:
Ans-
rubber,
glass,
dry wood,
iron
Q – 60 The lowest frequency that determines the pitch of a musical note is most commonly called the:
Ans- fundamental
Q – 61 According to Coulombs Law, if two charged particles are repelled with a given force at a distance d, by what multiple will the force decrease by if d is increased by 4 times?
Ans- 16 times
Q – 62 Which of the following is the most accurate reason why a light bulb dropped on a rug does not break, but when dropped on a tile floor it does break:
Ans-
1. the time it takes to stop moving is less for the tile
2. the change in momentum is greater for the tile
3. the light bulb weighs more when it hits the tile
4. the change in momentum is greater for the rug
Answer: A
Q – 63 Certain products have been designed so that people wearing headphones do not hear the objectionably loud sound from certain machinery with which they are working. These headphones most likely work based on which one of the following principles:
Ans-
1. doppler effect
2. destructive interference
3. constructive interference
4. audiopolarization
Answer: B
Q – 64 For particles that have mass, such as electrons, quantum theory gives the relationship of wavelength to momentum by which of the following formulas, where c is the speed of light, v is the particles speed, h is Plancks constant, m is the particles mass, and f is frequency:
Ans-
1. wavelength = mc2
2. wavelength = c / ƒ
3. wavelength = h /mv
4. wavelength = hf
Answer: C
Q – 65 The Department of Energys B-Factory at the Stanford Linear Accelerator Lab is designed to collide electron and positron beams of unequal energies and produce millions of these particles, which are commonly called:
Ans-
1. B mesons
2. B leptons
3. B muons
4. B neutrons
Q – 66 Which of the following is NOT an example of a transverse wave:
Ans-
1. ocean wave
2. light wave
3. microwave
4. sound wave
Q – 67 Which of the following is NOT true of Guglielmo Marconis experiments on wireless transmission:
Ans-
1. in 1901 he transmitted a signal from Newfoundland to England
2. he defied current belief on line-of-sight transmission
3. his work was a practical application of the work of James Clerk Maxwell
4. his success was a vindication of his belief in the reflective properties of the ionosphere
Q – 68 The atoms nucleus is held together by which of the following:
Ans-
1. strong interactions of the quark and gluon constituents of the atom’s nucleus
2. strong interactions of the quark and lepton constituents of the atom’s nucleus
3. weak interactions of the quark and lepton constituents of the atom’s nucleus
4. strong interactions of the lepton and gluon constituents of the atom’s nucleus
Q – 69 A figure skater who, while spinning in place, pulls her arms in to increase her rotational speed, is most closely exhibiting which of the following:
Ans- 1. conservation of angular momentum
2. centrifugal force
3. satellite motion
4. centripetal acceleration
Q – 70 Physicists most commonly call a mass moving in a straight line path as having:
Ans-
1. angular or rotational momentum
2. straight momentum
3. translational momentum
4. second order momentum
Q – 71 In beta minus emission, the number of nucleons in the atom:
Ans-
1. increases by one
2. decreases by one
3. increases by four
4. remains the same
Q – 72 What is a thermal transformation?
Ans- A chemical or physical change not requiring a change in the temperature of the substance, as in the formation of marten site.
Q – 73 When are intermolecular forces the strongest?
Ans- Intermolecular forces (dipole-dipole, dispersion and hydrogen bonds). These forces are weaker than chemical (covalent) bonds. Therefore molecular solids are soft, and have a generally low melting temperature.
Q – 74 Can a vector have a component equal to zero and still have a nonzero magnitude?
Ans- Yes. For instance, the 2-dimensional vector (1,0) has length sqrt(1+0) = 1
A vector only has zero magnitude when all its components are 0.
Q – 75 If a plane is in the air and there is a fly flying inside the plane does the plane get heavier when the fly lands?
Ans- yes. A fly puts weight on a plane gosh!!!! It’s like asking does a normal person put weight on a bike!? But yes fly do put weight on a plane that is flying if it lands, but it doesn’t put a lot of weight on because they are so small. There is your answer…
Q – 76 What is the cause of Brownian motion?
Ans- Molecules in a gas move constantly, freely, randomly, in all directions and at high speeds. They are able to do so because the intermolecular force of attraction between the molecules is negligible when in a gaseous state.
This constant motion of the molecules causes them to collide with anything in their path. For example, dust particles will be bombarded by the molecules moving at high speeds, causing them to have a zigzag motion.
Brownian motion also takes place in molecules in a liquid, but to a less obvious extent than in a gas.
Q – 77 How do you separate Hydrogen and Oxygen gases in industrial electrolysis of water process?
Ans- In electrolysis, oxygen and hydrogen gas are produced at different electrodes (oxygen at the anode and hydrogen at the cathode). Since these electrodes do not have to be in close proximity, the hydrogen and oxygen will bubble upwards into separate collection vessels.
If you needed to separate hydrogen and oxygen once mixed, the easiest way I can think of would be to cool the mixture to ~60K. At this point the oxygen would condense and leave hydrogen gas.
Q – 78 What is the universal law of universal gravitation?
Ans- statement that any particle of matter in the universe attracts any other with a force varying directly as the product of the masses and inversely as the square of the distance between them. In symbols, the magnitude of the attractive force F is equal to G (the gravitational constant, a number the size of which depends on the system of units used and which is a universal…
Q – 79 What is Centrifugal Force?
Ans- Centrifugal force is the force that is equal in magnitude but opposite in direction to the centripetal force, which is the force directed toward the center of a rotating or revolving mass.
Think of it this way. Let’s say you have a yo-yo and let it unwind. Then you start swinging it around your head in a circle parallel to the ground. The force that keeps the yo-yo in its circular path is the centripetal force.
Without it, the yo-yo would not continue in its circular path but would fly off in a straight line, which it is inclined to do. The tension in the string, the force that makes the string taut, is the centrifugal force.
Q – 80 What is a galvanometer and its use?
Ans- It’s an ammeter. It’s used to detect and measure electric current.
Q – 81 How much does two pints of water weigh when frozen?
Ans- The same it weighed when it was liquid—but it has a greater volume because ice is “fluffier” than water.
Q – 82 Does gas have density?
Ans- Gas, as well as everything in the universe has density, though some densities are either too high or too low to be detected, observed or measured by the human eye nor the technological gadgetry designed and used by scientists for that specific purpose
Q – 83 Which is heavier the land mass or the sea?
Ans- The land mass is heavier even tough the sea covers 2/3 of the earth’s surface it still has land under the sea hence it is heavier…
Q – 84 What is the difference between dynamic strain aging and strain aging?
Ans- Strain aging could be described as ” normal wear and tear ” or the fatigue that is experienced under normal conditions, whereas Dynamic strain would be an out of the normal range stress condition like a one time over stress condition where the sum of much strain aging is experienced in one ” dynamic” occurrence.
Q – 85 What is a crest?
Ans- In electromagnetic waves — or ocean waves, for that matter — a crest is the peak, or maximum height, of the waveforms. A trough is the lowest point. The wavelength of a wave is measured from one crest (peak) to the next or from one trough to the next.
Q – 86 Why does a tea kettle sing?
Ans- There is a small attachment with a hole in it which acts as a whistle. It is inserted into the spout of the kettle and when the water starts to boil, the steam makes a sound as it escapes.
Q – 87 What is the difference between a lens and a mirror?
Ans- A mirror is a reflective surface. Light passes through the glass and hits the silver backing, reflecting off of it. (The angle of incidence equals the angle of reflection.) A lens, on the other hand, does not reflect light; it refracts it.
After entering the glass, light refracts differently depending on the shape of the lens and also creates a focal point where the refracting light comes to a point. This differs for different lenses — convex or concave — which is why there are different lenses for different types of eyeglasses.
Q – 88 Which way do twin screw props on a boat rotate when propelling the boat forward?
Ans- In opposite direction, but they are designed to propel the boat forward even if they rotate in opposite directions.
Q – 89 What is ion pair energy?
Ans- ION ENERGY CONSISTS OF ELECTRIC CHARGES CALLED PROTONS (+), NUTRONS (0) AND ELECTRONS (-) CHARGES.ITS PRESENT IN AN ATOMIC SHELL.CHARGES +- CANCEL EACH OTHER TO KEEP BALANCE….
Q – 90 What is astrophysics?
Ans- The study of stars, galaxies, and the creation of the universe, including predictions about how it will proceed from here.
Q – 91 What is radium used for?
Ans- Radium was formerly used in self-luminous paints for watches, nuclear panels, aircraft switches, clocks, and instrument dials. More than 100 former watch dial painters who used their lips to shape the paintbrush died from the radiation from the radium that had become stored in their bones. Soon afterward, the adverse effects of radioactivity became widely known.
Radium was still used in dials as late as the 1950s. Although tritium’s beta radiation is potentially dangerous if ingested, it has replaced radium in these applications.
Q – 92 What is pascal s principle?
Ans- Pascal’s Principle states that the pressure is transmitted evenly through a liquid. That’s why when you inflate a balloon with air it expands evenly in all directions.
Q – 93 How does the arrangement of atoms in most solids differ from the arrangement of atoms in a liquid?
Ans- The arrangement of atoms in solids are different from those in liquids in that they are unable to move from their location in the solid, where they can move in the liquid.
A solid’s atoms are vibrating very rapidly, but the molecules are all locked into place, whereas in a liquid the molecules are free to move around. Also in general the atoms of a solid are closer together than those of a liquid with the exception of water, whose solid form is less dense.
Q – 94 When an object moves with constant velocity does its average velocity during any time interval differ from its instantaneous velocity at any instant?
Ans- No. Its velocity, average velocity and instantaneous velocity will all be the same at any (or every) time an investigator makes an observation.
Q – 95 When gravity is the only force acting on an object the object is in what?
Ans- One answer is that it is in free-fall in a vacuum (to eliminate atmospheric drag).
Another answer is that it is in orbit around another body.
The object could be in inter-stellar space, essentially experiencing the balanced gravitational force of “everything”.
If you eliminate the “middle of space” solution, the object would have to be in a state of acceleration.
Q – 96 What is cardiac output?
Ans- Cardiac output is the volume of blood the heart pumps within one minute. Cardiac output (CO) is equal to the stroke volume (SV) of the heart multiplied by the heart rate (HR). Thus, cardiac output is given by the equation: CO=HR X SV.
Q – 97 What is the longest lasting synthetic periodic element?
Ans- A good candidate would be curium 247 (247Cm), which has a half-life of 1.56 × 107 years. That’s 15,600,000 years (15.6 million years).
Q – 98 What happens when you travel across the dateline?
Ans- If westbound, the day changes to the next day. If eastbound, the day is the day before. Seems strange, but it all works out.
Let’s imagine we’re on the beach in the early evening west of the dateline at 4:59 PM Tuesday. If we swim eastward across the dateline and continue east seven time zones, it will be 11:59 PM Monday. We rest from all this exercise and ponder the strangeness of turning back a day. Whew! One more minute and it will be Tuesday anyway.
Continue 17 more time zones (24 totals) eastward and it will be 4:59 PM Tuesday. Just like we left it. It works just fine in the reverse going the other way.
Q – 99 What is the direction of null vector?
Ans- There are two possible answers to this;
a) It has no direction
b) It points in all directions
Q – 100 If a dog rolled around on a carpet and gets statically and a flea jumps on it will the flea get electrocuted?
Ans- it will, but probably, not and such experiment would be interesting one. Electrostatic electricity has a big potential – thousands volts – but small power when it gets discharged, that meaning the potential will subsides momentarily to null volts with the current caused very negligible.
This current will make little harm to the flea which, besides. consist of very resistive substance. The current might knock over the insect, but won’t kill it, I believe.