Scientific Units Practice Questions
19 free Scientific Units practice questions for the Static GK. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
Which of the following is the SI base unit of thermodynamic temperature?
- A Celsius
- B Fahrenheit
- C Kelvin
- D Rankine
Correct answer: Kelvin
Kelvin (K) is the SI base unit for temperature. Unlike Celsius or Fahrenheit, the Kelvin scale is an absolute scale starting at absolute zero, where molecular motion ceases.
The 'Pascal' is the SI derived unit used to measure which physical quantity?
- A Force
- B Pressure
- C Energy
- D Momentum
Correct answer: Pressure
One Pascal (Pa) is defined as one Newton per square meter. It is used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength.
Which unit is used to measure the intensity of sound?
- A Decibel
- B Hertz
- C Tesla
- D Coulomb
Correct answer: Decibel
The decibel (dB) is a relative unit of measurement used to express the ratio of one value of a power or field quantity to another on a logarithmic scale. It is the standard unit for sound level.
Which unit is used to measure the frequency of a periodic wave?
- A Joule
- B Hertz
- C Newton
- D Farad
Correct answer: Hertz
Hertz (Hz) is the unit of frequency in the International System of Units (SI). One hertz is defined as one cycle per second.
The 'Light-year' is a unit of measurement for:
- A Time
- B Speed
- C Distance
- D Luminosity
Correct answer: Distance
A light-year is the distance that light travels in a vacuum in one Julian year. It is used to express astronomical distances, such as the distance between stars or galaxies.
Which of the following is the SI unit of luminous intensity?
- A Lumen
- B Lux
- C Candela
- D Steradian
Correct answer: Candela
The candela (cd) is the SI base unit of luminous intensity. It measures the luminous power per unit solid angle emitted by a point light source in a particular direction.
Which unit is used to measure the power of a lens?
- A Dioptre
- B Degree
- C Radian
- D Angstrom
Correct answer: Dioptre
The power of a lens is measured in dioptres (D). It is the reciprocal of the focal length of the lens measured in meters.
The SI unit of magnetic flux density is named after which scientist?
- A Michael Faraday
- B James Clerk Maxwell
- C Nikola Tesla
- D André-Marie Ampère
Correct answer: Nikola Tesla
The Tesla (T) is the SI derived unit of magnetic flux density. One tesla is equal to one weber per square meter.
Which of the following units is used to measure the amount of a substance in chemistry?
- A Gram
- B Kilogram
- C Mole
- D Liter
Correct answer: Mole
The mole (mol) is the SI base unit for the amount of substance. One mole contains exactly 6.02214076 × 10^23 elementary entities (Avogadro's number).
The 'Newton' is the SI unit of force. One Newton is equal to:
- A 1 kg·m/s
- B 1 kg·m/s²
- C 1 g·cm/s²
- D 1 kg·m²/s²
Correct answer: 1 kg·m/s²
One Newton (N) is the force needed to accelerate one kilogram of mass at the rate of one meter per second squared. It is derived from Newton's Second Law ($F=ma$).
Which unit is used to measure the electrical resistance of a conductor?
- A Farad
- B Henry
- C Ohm
- D Siemens
Correct answer: Ohm
The Ohm (Ω) is the SI unit of electrical resistance. It is named after German physicist Georg Simon Ohm and is defined as the resistance between two points of a conductor when a constant potential difference of one volt applied to these points produces a current of one ampere.
Which unit is used to measure the depth of the sea?
- A Knot
- B Fathom
- C Nautical Mile
- D Light-year
Correct answer: Fathom
A fathom is a unit of length in the imperial and U.S. customary systems equal to 6 feet (1.8288 meters). It is used especially for measuring the depth of water.
The 'Joule' is the SI unit of:
- A Force
- B Energy
- C Power
- D Pressure
Correct answer: Energy
The Joule (J) is the SI unit for energy, work, or amount of heat. It is equal to the work done by a force of one Newton acting through a distance of one meter.
What is the SI unit of capacitance?
- A Henry
- B Tesla
- C Weber
- D Farad
Correct answer: Farad
The Farad (F) is the SI unit of electrical capacitance. It is named after the English physicist Michael Faraday and represents the ability of a body to store an electrical charge.
Which unit is used to measure the speed of a ship?
- A Mach
- B Knot
- C Nautical Mile
- D Fathom
Correct answer: Knot
A knot is a unit of speed equal to one nautical mile per hour. It is widely used in meteorology, maritime navigation, and air navigation.
The unit 'Angstrom' is used to measure which of the following?
- A Length
- B Mass
- C Time
- D Torque
Correct answer: Length
An Angstrom (Å) is a non-SI unit of length equal to 10^-10 meters. It is primarily used to express the sizes of atoms, molecules, and the wavelengths of electromagnetic radiation.
Which unit is used to measure the radioactivity of a substance?
- A Becquerel
- B Roentgen
- C Sievert
- D Curie
Correct answer: Becquerel
The Becquerel (Bq) is the SI derived unit of radioactivity. One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second.
The unit of atmospheric pressure is:
- A Bar
- B Joule
- C Erg
- D Newton
Correct answer: Bar
A bar is a metric unit of pressure, but not part of the SI. It is approximately equal to the atmospheric pressure on Earth at sea level (1 bar = 100,000 Pa).
Which unit is used to measure the thickness of the Ozone layer?
- A Micron
- B Angstrom
- C Nanometer
- D Dobson
Correct answer: Dobson
The Dobson Unit (DU) is the most common unit for measuring ozone concentration. One DU is the number of molecules of ozone that would be required to create a layer of pure ozone 0.01 millimeters thick at a temperature of 0°C and a pressure of 1 atmosphere.