Physics Chemistry & Biology Test 1
The Bhopal Gas Tragedy was caused by :
  • Phosgen gas
  • Carbon monoxide
  • Methyl isocyanate
  • Chlorine
Explanation:

The Bhopal Gas Tragedy, which occurred in 1984, was caused by the release of methyl isocyanate (MIC) gas.

This highly toxic substance was stored in a pesticide plant and its accidental release led to one of the worst industrial disasters in history, causing thousands of deaths and injuries.

The pale yellow colour of urine is due to the presence of which pigment?
  • Urophyll
  • Urochrome
  • Chlorophyll
  • Chloroplast
Explanation: The pale yellow color of urine is primarily due to the pigment urochrome, which is a byproduct of the breakdown of hemoglobin from red blood cells. Urochrome is responsible for the yellow hue and varies in intensity depending on hydration levels and other factors.
Where is 'Dakshin Gangotri' located ?
  • South Pole
  • Himalaya
  • Uttarakhand
  • Antarctica
Explanation: Dakshin Gangotri is an Indian research station located in Antarctica. It was established in 1983 and was one of the first Indian stations set up on the continent to support scientific research. It is not to be confused with locations in the Himalayas or Uttarakhand.
Which gas is used as fire extinguisher?
  • Nitrogen dioxide
  • Carbon monoxide
  • Carbon dioxide
  • Nitrous oxide
Explanation: Carbon dioxide (CO₂) is commonly used in fire extinguishers. It works by displacing oxygen around the fire, thus smothering the flames and preventing the fire from continuing. CO₂ extinguishers are effective for electrical fires and flammable liquids.
A fan produces a feeling of comfort during hot weather because:
  • fan supplies cool air
  • our body radiates more heat in air
  • conductivity of air increases
  • our perspiration evaporates rapidly
Explanation: A fan produces a feeling of comfort in hot weather by increasing air circulation, which enhances the evaporation of perspiration from the skin. This process helps to cool the body, as evaporation absorbs heat, making the environment feel cooler even though the fan does not lower the air temperature itself.
What is the unit for measuring the intensity of sound ?
  • Decibel
  • Coulomb
  • Henry
  • Hertz
Explanation: The intensity of sound is typically measured in decibels (dB). The decibel scale is a logarithmic unit used to express the ratio of one value of a physical property to another on a logarithmic scale. In the context of sound, it measures the power or intensity of sound waves. Here's a brief explanation of the other units listed in the options to clarify why they are not used for measuring sound intensity: Coulomb (C): This is the unit of electric charge in the International System of Units (SI). It measures the amount of electric charge transported by a constant electric current of one ampere in one second. Henry (H): This is the unit of inductance in the SI system. It measures the ability of an inductor to store energy in a magnetic field. Hertz (Hz): This is the unit of frequency in the SI system. It measures the number of cycles per second of a periodic phenomenon, such as sound waves or electromagnetic waves. In summary, decibel (dB) is the correct unit for measuring the intensity of sound because it quantifies the power level of sound waves, indicating how loud a sound is perceived.
Restarting of computer that is already on is referred to as:
  • Cold booting
    • Explanation: A warm boot, also known as a "soft reboot," refers to the process of restarting a computer system without completely shutting down the power. This is typically done using the operating system's restart function, which reinitializes the system and reloads the operating system without turning off the hardware. Here are the terms explained again for clarity: Cold booting (A): Also known as a "cold start," this refers to starting a computer from a completely powered-down state. This involves turning on the power switch and initializing the system from scratch. Logging off (B): This refers to ending the current user session, allowing another user to log in without shutting down the computer. It does not restart the computer. Shut down (C): This refers to turning off the computer completely, ending all processes and cutting power to the system. Warm booting (D): This is the process of restarting a computer that is already on, without turning off the power. It involves reloading the operating system and reinitializing the hardware and software components. In summary, warm booting is the correct term for restarting a computer system without completely shutting down the power.