Physics Chemistry & Biology Test 6
Which one of the following is an active component of oil of clove?
  • Eugenol
  • Benzaldehyde
  • Menthol
Explanation: Eugenol is the active component of clove oil, responsible for its strong aroma and medicinal properties. It is widely used in dentistry as a pain reliever and has antibacterial and anti-inflammatory effects.
Which one of the following is the longest flower in the world?
  • Rafflesia
  • Glory lily
  • Lotus
  • Sunflower
Explanation: Rafflesia arnoldii produces the largest individual flower in the world, measuring up to 3 feet (1 meter) in diameter. It is a parasitic plant with a strong odor resembling rotting flesh, which helps attract pollinators like flies.
Which of the following bears naked seeds?
  • Angiosperms
  • Bryophytes
  • Pteridophytes
  • Gymnosperms
Explanation: Gymnosperms are seed-producing plants that bear naked seeds, meaning their seeds are not enclosed within a fruit. Examples include pine, fir, and cycad trees.
Water equivalent is equal to the product of
  • latent heat and volume of water
  • mass and specific heat
  • mass and gas constant
  • mass and avogadro number
Explanation: Water equivalent (W) is defined as the mass of water that would absorb the same amount of heat as a given substance for the same temperature rise. It is given by: 𝑊 = W=m×c where: m = mass of the substance c = specific heat capacity of the substance Thus, water equivalent is equal to the product of mass and specific heat.
The gas released during the photosynthesis by the green plants is
  • Nitrogen
  • Oxygen
  • Water vapour
  • Carbon dioxide
Explanation: During photosynthesis, green plants use sunlight to convert carbon dioxide (CO2) and water (H2O) into glucose (C6H12O6 ) and oxygen (O2). The overall reaction is: 6CO2+6H2O+Light Energy→C6H12O6 + 6O2 Oxygen is released as a byproduct of this process and is essential for respiration in most living organisms.
In which mode of transmission, the heat waves travel along straight line with the speed of light?
  • thermal conduction
  • natural convection
  • thermal radiation
  • forced convection
Explanation: Thermal radiation is the mode of heat transfer in which heat energy is emitted in the form of electromagnetic waves (mainly infrared radiation). These waves travel in a straight line at the speed of light (≈ 3 × 10⁸ m/s) and do not require a medium for transmission. Examples of thermal radiation: Heat from the Sun reaching Earth Heat emitted by a fire or an electric heater
Which of the following metals is found in the chlorophyll?
  • Cobalt
  • Zinc
    • Explanation: Chlorophyll, the green pigment essential for photosynthesis in plants, contains magnesium (Mg) at its core. This magnesium ion (Mg²⁺) is crucial for capturing light energy and aiding in the conversion of sunlight into chemical energy.