1. In the following which is fundamental physical quantity?
(a) Force
(b) Velocity
(c) Electric current
(d) Work
(e) None of the above/More than one of the above
[66th B.P.S.C. (Pre) (Re. Exam) 2020]
Ans. (c) Electric current
- In physics, there are seven basic physical measurements (which are measured using basic units): length, mass, time, electric current, temperature, light intensity, and amount of something.
|
2. The unit of power is –
(a) Hertz
(b) Volts
(c) Watt
(d) Neutron
[U.P.P.S.C. (GIC) 2010]
Ans. (c) Watt
- Power is a measure of how fast energy is being used or transferred.
- It is calculated by dividing the amount of work done (in joules) by the time it takes to do the work (in seconds).
- The basic unit of power is the watt, which is equal to one joule per second.
- Power is usually written as watts (W) or kilowatts (KW).
|
3. The unit of electric power is :
(a) Ampere
(b) Volt
(c) Coulomb
(d) Watt
(e) None of the above / More than one of the above
[65th B.P.S.C. (Pre) 2019, 64th B.P.C.S. (Pre) 2018]
Ans. (d) Watt
- Electric power is how quickly electrical energy moves through a circuit.
- Its unit in the SI system is called the watt.
- Ampere is the unit of electric current, voltage is the unit of electrical potential and coulomb is the unit of electric charge.
|
4. The unit of the force is –
(a) Faraday
(b) Fermi
(c) Newton
(d) Rutherford
[M.P.P.C.S. (Pre) 1990]
Ans. (c) Newton
- Force is a physical concept that causes something to move.
- The measurement of force is in Newtons (or kg.m/sec²).
- This is based on Isaac Newton’s law which states that force is equal to the mass of an object multiplied by its acceleration.
|
5. The unit of work is :
(a) Joule
(b) Neutron
(c) Watt
(d) Dyne
[U.P.P.C.S. (Pre) 1996]
Ans. (a) Joule
- When a force causes something to move, the work done is equal to the amount of force multiplied by how far the object moves in the direction of the force.
- This is a number without direction.
- The unit used to measure work is the Newton metre, which is also known as a joule.
- The joule is also the unit of energy.
|
6. Frequency is measured in
(a) hertz
(b) metre/second
(c) radian
(d) watt
(e) None of the above / More than one of the above
[64th B.P. S.C. (Pre) 2018]
Ans. (a) hertz
- The Hertz, which is represented by the symbol Hz, is a unit of measurement for frequency used in the International System of Units (SI system).
- It is equal to one cycle per second.
|
7. What is measured in hertz?
(a) Frequency
(b) Energy
(c) Heat
(d) Quality
(e) None of the above/More than one of the above
[65th B.P.S.C. (Pre) 2019]
Ans. (a) Frequency
- Frequency is how often something happens in a certain amount of time.
- One hertz is the same as one event happening every second.
|
8. The SI unit of electrical resistivity of the conductor is –
(a) Faraday
(b) Volts
(c) Ampere
(d) Ohm
[M.P.P.C.S. (Pre) 1993]
Ans. (*)
- Electrical resistivity is a property that measures how well a material allows electricity to flow through it.
- A low resistivity means that the material lets electricity flow easily.
- The unit of resistivity is ohm-meter.
- It is usually shown by the Greek letter ρ, which stands for the ratio of the material’s electrical resistance and its length.
- Faraday is the unit for capacitance, volt is the unit for electric potential, ampere is the unit for electric current and ohm is the unit for electrical resistance (not resistivity).
|
9. ‘Ohm-meter’ is a unit of :
(a) Resistance
(b) Conductance
(c) Resistivity
(d) Charge
(e) None of the above/More than one of the above
[66th B.P.S.C. (Pre) (Re. Exam) 2020]
Ans. (c) Resistivity
- The ohm-meter (ohm-m) is a measure of resistivity, which is the ability of a material to resist the flow of electricity.
- The standard unit of electrical resistivity is the ohm-meter, represented by the symbol ⍴.
|
10. Light-year is the unit of –
(a) Distance
(b) Time
(c) Speed of light
(d) Intensity of light
[U.P. U.D.A./L.D.A. (Pre) 2013, R.A.S./R.T.S. (Pre) 1997, M.P.P.C.S. (Pre) 2008]
Ans. (a) Distance
- Light-year is a unit of measurement used to measure distances in space.
- It is equal to the amount of distance that light can travel in one year, which is 9.46 trillion kilometres
|
11. A light-year is the –
(a) Year which had maximum sunlight
(b) Year in which workload was very light
(c) Distance travelled by light in one year
(d) Mean distance between Sun and Earth
[U.P. Lower Sub. (Mains) 2013]
Ans. (c) Distance travelled by light in one year
- A light-year is the amount of distance that light can cover in a single year.
- Light moves at a rate of 186,000 miles per second or 5.88 trillion miles in a year.
|
12. Light-year is the unit of –
(a) Energy
(b) Intensity
(c) Age
(d) Distance
[Jharkhand P.C.S. (Pre) 2013]
Ans. (d) Distance
- A light-year is a measure of how far away something is.
- It is the amount of distance that light can travel in one year.
|
13. ‘Light-Year’ is –
(a) The year in which February has 29 days
(b) The distance travelled by light in one year
(c) The time which sun rays take to reach the earth
(d) The time in which a spacecraft reaches moon from the earth
[U.P. U.D.A./L.D.A. (Pre) 2010]
Ans. (b) The distance travelled by light in one year
- A light-year is how far light goes in one year.
- Light moves at 186,000 miles every second, and 9.46 trillion kilometres each year.
|
14. Which one of the following is a reason why astronomical distances are measured in light-years?
(a) Distances among stellar bodies do not change
(b) Gravity of stellar bodies does not change
(c) Light always travels in straight line
(d) Speed of light is always same
[I.A.S. (Pre) 2021]
Ans. (d) Speed of light is always same
- A light-year is the amount of space a beam of light can travel in one year on Earth.
- Light travels at a constant speed in a vacuum, which is an area without any gravity.
- This speed is the same throughout the universe and is very accurately known.
- That is why astronomers use light-years to measure distances in space.
|
15. A parsec, a unit of distance used to measure the distance related to the stars in the sky, is equal to –
(a) 4.25 light-years
(b) 3.25 light-years
(c) 4.50 light-years
(d) 3.05 light-years
[R.A.S./R.T.S. (Pre) 1999]
Ans. (b) 3.25 light-years
- A parsec is a unit of length that is utilized to quantify the vast distances of celestial objects located outside of our solar system.
- It is equal to approximately 3.08 × 10^16 meters. In comparison, a light-year is equivalent to about 9.46 × 10^15 meters.
- Therefore, 1 parsec is approximately equal to 3.256 light-years.Based on the given options, only option (b) is in close proximity to the accurate answer.
|
16. PARSEC is the unit of :
(a) Distance
(b) Time
(c) Light intensity
(d) Magnetic force
[U.P.P.C.S. (Pre) 1997]
Ans. (a) Distance
- Parsec is a unit of measurement used to measure the large distances between objects in space.
- It is equal to 3.26 light years or the distance at which one astronomical unit subtends an angle of one arc second.
|
17. Which unit of measurement is multiplied by 0.39 to convert it to ‘inches’?
(a) Millimetre
(b) Centimetre
(c) Metre
(d) Decimetre
[U.P. U.D.A./L.D.A. (Pre) 2010]
Ans. (b) Centimetre
- 1 cm is equal to 0.39 inches, so to change cm to inches, we need to multiply it by 0.39.
|
18. How can the height of a person who is six feet tall, be expressed (approximately) in nanometre?
(a) 183 × 106nm
(b) 234 ×106nm
(c) 183 × 107nm
(d) 181 × 107nm
[I.A.S. (Pre) 2008]
Ans. (c) 183 × 107nm
- One nanometer is equivalent to 10^-9 meters.
- One foot is equal to 0.305 meters.
- One foot is equal to 30.5 × 10^7 nanometers.
Thus, 6 feet is equal to 6 × 30.5 × 10^7 nanometers, which is equal to 183 × 10^7 nanometers.
|
19. A nanometre is equal to –
(a) 10-6 cm
(b) 10–7 cm
(c) 10-8 cm
(d) 10-9 cm
[U.P. U.D.A./L.D.A. (Pre) 2013]
Ans. (b) 10–7 cm
- One nanometer is equal to 1.0 × 10^-9 meters.
- Since 1 meter is equivalent to 100 centimeters, then 10^-9 meter is equal to 10^2 × 10^-9 centimeters, which simplifies to 10^-7 centimeters.
|
20. Ampere is the unit of –
(a) Voltage
(b) Electric current
(c) Resistance
(d) Power
[Chhattisgarh P.C.S. (Pre) 2005]
Ans. (b) Electric current
- Ampere is the way we measure electric current. If there is one ampere of current going through a wire, it means that 6.25 x 1018 electrons are flowing in each direction each second.
|
21. Megawatt is the measuring unit of power which is –
(a) Generated
(b) Consumed
(c) Saved
(d) Lost in transmission
[U.P. Lower Sub. (Pre) 1998]
Ans. (a) Generated
- A megawatt is a unit of power that is produced by power plants and power stations.
- One megawatt is equal to 1 million watts.
|
22. Match List-I with List-II and select the correct answer from the code given below :
| List-I |
List-II |
| (Physical quantities) |
(Units) |
| A. Acceleration |
1. Joule |
| B. Force |
2. Newton second |
| C. Work done |
3. Newton |
| D. Impulse |
4. Metre/second² |
Code :
A B C D
(a) 1 2 3 4
(b) 3 4 1 2
(c) 2 3 4 1
(d) 4 3 1 2
[U.P.P.C.S. (Pre) 2005, U.P. U.D.A./L.D.A. (Pre) 2001]
Ans. (d) 4 3 1 2
- Acceleration describes how quickly something is speeding up or slowing down, measured over a period of time.
- The standard unit for acceleration is metres per second squared (m/s²).
- The standard unit for force is newtons (N), the standard unit for impulse is newton seconds (Ns), and the standard unit for work is joules (J).
|
23. Which one of the following SI units is not correctly matched?
(a) Work – Joule
(b) Force – Newton
(c) Mass – kg.
(d) Pressure – Dyne
[U.P. Lower Sub. (Pre) 2013]
Ans. (d) Pressure – Dyne
- Pascal is a unit of pressure or stress that is used in the International System of Units.
- Dyne is a unit of force that is used in the CGS system.
- Option (d) does not match up correctly.
|
24. Match List-I with List-II and select the correct answer using codes given below :
| List-I |
List-II |
| (Units) |
(Parametric quantities) |
| A. Watt |
1. Heat |
| B. Knot |
2. Navigation |
| C. Nautical mile |
3. Speed of a ship |
| D. Calorie |
4. Power |
Code :
A B C D
(a) 3 1 4 2
(b) 1 2 3 4
(c) 4 3 2 1
(d) 2 4 1 3
[U.P. U.D.A./L.D.A. (Pre) 2002]
Ans. (c) 4 3 2 1
- RThe watt (W) is the standard unit of power, which equals one joule per second.
- The knot is used to measure the speed of a ship. Navigators use the nautical mile to measure distance.
- The calorie is the unit to measure heat and energy, making option (c) the correct answer.
|
25. Match the following :
| A. Joule |
1. Current |
| B. Ampere |
2. Power |
| C. Watt |
3. Work |
| D. Volt |
4. Electric potential |
Code :
A B C D
(a) 3 1 2 4
(b) 1 2 3 4
(c) 4 3 2 1
(d) 1 3 2 4
[U.P.P.C.S. (Pre) 1990]
Ans. (a) 3 1 2 4
- Joule is the measure of work used in the metric system.
- Ampere, watt and volt are the measurements of current, power and electrical potential.
|
26. How many watts are there in a horsepower?
(a) 1000
(b 750
(c) 746
(d) 748
[M.P.P.C.S. (Pre) 1991]
Ans. (c) 746
- Horsepower is a way to quantify the amount of work being done.
- One watt is equal to one joule per second and one horsepower is equal to 746 watts.
|
27. Which one of the following is not correctly matched?
(a) Knot – Measure of speed of ship
(b) Nautical mile – Unit of distance used in navigation
(c) Angstrom – Unit of wavelength of light
(d) Light year – Unit of measuring time
[U.P.P.C.S. (Mains) 2010]
Ans. (d) Light year – Unit of measuring time
- A light year is not a way to measure time, but a way to measure distance.
- The other pairs are matched correctly.
|
28. Angstrom is a unit of
(a) wavelength
(b) energy
(c) frequency
(d) velocity
(e) None of the above / More than one of the above
[64th B.P.C.S. (Pre) 2018]
Ans. (a) wavelength
- The Angstrom is a unit of length, usually used to measure the wavelength of light.
- It’s equal to 0.1 nanometres or 10-10 metres.
- It was named after a 19th century Swedish physicist, Anders Jonas Angstrom.
|
29. Match List-I (Quantity) with List-II (Units) and select the correct answer using the codes given below the lists:
| List I |
List II |
| A. High speed |
1. Mach |
| B. Wavelength |
2. Angstrom |
| C. Pressure |
3. Pascal |
| D. Energy |
4. Joule |
Code :
A B C D
(a) 2 1 3 4
(b) 1 2 4 3
(c) 1 2 3 4
(d) 2 1 4 3
[U.P.P.C.S. (Pre) 2006, I.A.S. (Pre) 1999]
Ans. (c) 1 2 3 4
- The Mach number is a way to compare the speed of something to the speed of sound.
- If an object is going faster than the speed of sound, it is said to be travelling at supersonic speed (Mach 1).
- Mach is a measure of high speed. Wavelength is measured in angstroms, pressure in pascals, and energy in joules.
|
30. ‘Joule’ is related to energy in the same way as ‘Pascal’ is related to :
(a) Mass
(b) Pressure
(c) Density
(d) Purity
(e) None of the above
[Chhattisgarh P.C.S. (Pre) 2015]
Ans. (b) Pressure
- The right answer is pressure.
- Joule is a measure of energy in the International System of Units (SI), and Pascal is the measure of pressure in the SI.
|
31. One micron is equal to –
(a) 1/10 mm
(b) 1/100 mm
(c) 1/1000 mm
(d) 1/10,000 mm
[39th B.P.S.C. (Pre) 1994]
Ans. (c) 1/1000 mm
- One micron is equal to 10^-6 meters.
- This is equivalent to 10^-6 multiplied by 10^3 millimeters, which simplifies to 1/1000 millimeter.
|
32. One micron represents a length of –
(a) 10-6 cm
(b) 10-4 cm
(c) 1 mm
(d) 1 m
[U.P.P.C.S. (Mains) 2011]
Ans. (b) 10-4 cm
- A micron signifies a measurement of 10^-6 meters and is denoted by the symbol “µ.”
- This is equivalent to 0.000001 meters or 0.0001 centimeters.
- In other words, it can be expressed as 1/1000 or 1/10^4 centimeters, which simplifies to 10^-4 centimeters.
|
33. Which one of the following is not correctly matched?
(a) Decibel – Unit of sound intensity
(b) Horsepower – Unit of power
(c) Nautical miles – Unit of naval distance
(d) Celsius – Unit of heat
[U.P.P.C.S. (Spl.) (Mains) 2004, U.P.P.C.S.(Pre) 2001]
Ans. (d) Celsius – Unit of heat
- Celsius is a way to measure temperature. Calories measure heat.
- A nautical mile is a unit of distance that is equal to 1.852 kilometers.
- The SI unit of power is the watt, which is the same as a Joule per second.
- Horsepower and metric horsepower are also units of power and 1 horsepower is equal to 746 watts.
- Decibel is used to measure sound intensity.
|
34. Which one of the following is not the unit of heat?
(a) Calorie
(b) Kilocalorie
(c) Kilojoule
(d) Watt
[M.P. P.C.S. (Pre) 2016]
Ans. (d) Watt
- The watt is a type of measurement for power that comes from the International System of Units.
- All other measurements are for heat.
|
35. Which one of the following is not the unit of heat?
(a) Centigrade
(b) Calorie
(c) Erg
(d) Joule
[U.P. R.O./A.R.O. (Pre) 2017]
Ans. (a) Centigrade
- Temperature is how hot or cold something is.
- We measure it using a thermometer that is marked according to a temperature scale like Centrigrade, Fahrenheit or Kelvin.
- Heat energy is measured using the calorie, erg and joule and it is transferred from one thing to another when there is a difference in temperature.
- Heat is a type of energy.
|
36. A distance of 1 km. means –
(a) 100 m.
(b) 1000 cm.
(c) 1000 m.
(d) 100 cm.
[45th B.P.S.C. (Pre) 2001]
Ans. (c) 1000 m.
- Distance is measured in metres. One kilometre is the same as 1000 metres.
- One metre is the same as 100 centimetres.
|
37. One pikogram is equal to –
(a) 10–6 gram
(b) 10–9 gram
(c) 10–12 gram
(d) 10–15 gram
[42nd B.P.S.C. (Pre) 1997]
Ans. (c) 10–12 gram
- Mass is measured in small units called Milligrams (10-3 grams), Micrograms (10-6 grams), Pikograms (10-12 grams) and Femtograms (10-15 grams).
|
38. Pascal is a unit of measuring :
(a) Humidity
(b) Pressure
(c) Rainfall
(d) Temperature
[Uttarakhand P.C.S. (Pre) 2002]
Ans. (b) Pressure
- The pascal (Pa) is a unit of pressure or stress in the International System of Units (SI) that is named after the scientist Blaise Pascal.
- One pascal is equal to one newton of force applied over an area of one square metre, which is equivalent to 1kg/ms² or 1kg m–1s–2.
|
39. What is the unit of pressure?
(a) Newton / sq. metre
(b) Newton-metre
(c) Newton
(d) Newton/metre
(e) None of the above / More than one of the above
[64th B.P.C.S. (Pre) 2018]
Ans. (a) Newton / sq. metre
- The unit of measure for pressure is called pascal (Pa) and it is the same as one newton per square metre (N/m² or kg m-1s-2).
- It was given this name in 1971.
|
40. The unit of pressure is
(a) kg/cm²
(b) kg/cm
(c) kg/mm
(d) kg/cm³
(e) None of the above/More than one of the above
[65th B.P.S.C. (Pre) 2019]
Ans. (e) None of the above/More than one of the above
- The kilogram-force per square centimeter (kgf/cm²) is a pressure unit that is considered deprecated.
- It was commonly written as kilogram per square centimeter (kg/cm²), which is an incorrect expression for pressure.
- The correct representation should be kgf/cm².
|
41. What is the unit of atmospheric pressure?
(a) Bar
(b) Knot
(c) Joule
(d) Ohm
[Chhattisgarh P.C.S. (Pre) 2008]
Ans. (a) Bar
- The bar is a metric unit of pressure, although it is not part of the International System of Units (SI).
- It is defined as equal to 105 newtons per square meter.
- In contrast, the pascal is the SI unit of pressure.
- To clarify, 1 bar is equivalent to 105 pascals.
|
42. 1 kg/cm² pressure is equivalent to :
(a) 0.1 bar
(b) 1.0 bar
(c) 10.0 bar
(d) 100.0 bar
[Uttarakhand P.C.S. (Pre) 2002]
Ans. (b) 1.0 bar
- In this question, the term 1 kg/cm² is used to represent 1 kilogram-force per square centimeter (kgf/cm²).
- It is worth noting that 1 dyne is equivalent to 1.02 × 10^-6 kilogram-force (kgf). Additionally, 1 bar is equal to 10^6 dyne per square centimeter (dyne/cm²).
- Therefore, by substituting the value of dyne into the value of bar, we can determine that: 1 bar is equal to 10^6 dyne/cm², which is equivalent to 1.02 × 10^-6 × 10^6 kgf/cm².Hence, 1 bar is approximately equal to 1.02 kgf/cm².
|
43. Which one of the following quantities does not have unit?
(a) Stress
(b) Force
(c) Strain
(d) Pressure
(e) None of the above/More than one of the above
[65th B.P.S.C. (Pre) 2019]
Ans. (c) Strain
- Whenever an outside force changes the shape or size of an object, it is called strain.
- Since it is a ratio, it doesn’t have any units.
- Force is measured in newtons (kg m/s2) and stress and pressure are measured in pascals (kg m-1 s-2).
|
44. 1 barrel of oil is equal to which of the following?
(a) 131 litre
(b) 159 litre
(c) 179 litre
(d) 201 litre
[U.P.P.C.S. (Pre) 2009]
Ans. (b) 159 litre
- The amount of oil is now measured in cubic metres.
- 1 barrel = 158.9873 litre
- 1 barrel = 0.158987 cubic metre
- 1 barrel = 42 U.S. gallon
- 1 barrel = 34.9723 U.K. gallons.
|
45. The smallest unit of length is –
(a) Micron
(b) Nanometre
(c) Angstrom
(d) Fermimetre
[U.P.P.C.S. (Pre) 2005]
Ans. (d) Fermimetre
- Here are the rephrased statements:
- A micron is equal to 10^-6 meters.
- A nanometer is equal to 10^-9 meters.
- An angstrom is equal to 10^-10 meters.
- A fermi (femtometer) is equal to 10^-15 meters.
|
46. Match List-I with List-II and select the correct answer using the codes given below the lists.
| List – I |
List – II |
| A. Cusec |
1. Pressure |
| B. Byte |
2. Intensity of Earthquake |
| C. Richter |
3. Rate of flow |
| D. Bar |
4. Computer |
Code :
A B C D
(a) 1 2 3 4
(b) 3 4 2 1
(c) 4 3 2 1
(d) 3 4 1 2
[U.P. Lower Sub. (Spl.) (Pre) 2008]
Ans. (b) 3 4 2 1
- Cusec stands for cubic feet per second and is a way to measure how much water is flowing – it’s 28.317 litres per second.
- A byte is a unit of digital information which has 8 bits.
- The Richter magnitude scale is a way to work out the energy released by an earthquake.
- The bar is a metric unit of pressure and it is exactly the same as 100,000 Pascal.
|
47. What is measured in cusec?
(a) Purity of water
(b) Depth of water
(c) Flow of water
(d) Quantity of water
[Uttarakhand P.C.S. (Pre) 2006]
Ans. (c) Flow of water
- The irrigation department often uses Cusec to tell how much water is released from reservoirs.
|
48. Which one of the following is the unit of measure of the thickness of the ozone layer of the atmosphere?
(a) Knot
(b) Dobson
(c) Poise
(d) Maxwell
[Uttarakhand P.C.S. (Pre) 2010]
Ans. (b) Dobson
- The thickness of the ozone layer is measured with a unit called Dobson unit, which is the same as 0.01mm in the Earth’s atmosphere at normal temperature and pressure.
- This unit was named after G.M.B. Dobson, who studied ozone in the atmosphere.
- One Dobson unit is equal to 2.687 x 1020 molecules of ozone per square meter.
|
49. ‘Dobson’ Unit is used for the measurement of –
(a) Thickness of Earth
(b) Thickness of Diamond
(c) Thickness of the Ozone layer
(d) Measurement of Noise
[Uttarakhand P.C.S. (Pre) 2005]
Ans. (c) Thickness of the Ozone layer
- One Dobson unit (DU) is equal to 0.01 mm thickness when measured at the standard temperature and pressure.
- It was named after G.M.B. Dobson who studied ozone in the atmosphere.
- Each DU is the same as 2.687 x 1020 molecules of ozone per square meter.
|
