All Free Everyday Science MCQs with Answers

1861. Heavy mechanical complex use a large amount of water for_________?

• A. Cooling
• B. Freezing
• C. Washing
• D. Mixing

Explanation: Heavy mechanical equipment produces substantial heat through friction and operation, so water is commonly circulated to remove heat and prevent overheating. Freezing, washing and mixing are not the main purpose in this context.

1862. What charge card, developed in 1950, was the first to be accepted nationally in the US?

• A. Visa
• B. Discover
• C. MasterCharge
• D. Diner's Club

Explanation: Diners Club introduced the first widely accepted charge card in 1950, initially for use at restaurants and later across the United States. Visa and MasterCard came later, while Discover was introduced much later.

1863. When were blue jeans invented in _________?

• A. 1900s
• B. 1860s
• C. 1870s
• D. 1850s

Explanation: Modern blue jeans were developed by Levi Strauss and Jacob Davis and patented in 1873. That places their invention in the 1870s, although denim garments existed before this patent.

1864. The term "white coal" sometimes referred to which of the following?

• A. Geothermal Electricity
• B. Wind Energy
• C. Hydroelectricity
• D. Biomass Energy

Explanation: Hydroelectricity is called white coal because flowing or falling water produces clean electrical energy, analogous to coal as a power source. The term is not normally used for geothermal, wind or biomass energy.

1865. Which type of reaction produces the most harmful radiation?

• A. Fusion reaction
• B. Fission reaction
• C. Chemical reaction
• D. Photo-Chemical reaction

Explanation: Nuclear fission produces radioactive fragments and long-lived radioactive waste, making its radiation hazard greater than that of ordinary chemical or photochemical reactions. Fusion can also produce radiation, but it does not create the same large quantity of long-lived fission products.

1866. The electronic device which is used as a switch or amplifier is called ?

• A. Diode
• B. Resistor
• C. Transistor
• D. Transformer

Explanation: A transistor controls current and can operate as an electronic switch or amplify a signal. A diode mainly permits current in one direction, while a resistor limits current.

1867. Atomic power plant works on the principle of?

• A. fission
• B. fusion
• C. thermal combustion
• D. combined effect of all the above three

Explanation: An atomic power plant splits heavy atomic nuclei, commonly uranium-235, in a controlled chain reaction. The released nuclear energy heats water to produce steam and electricity, so the basic principle is fission.

1868. Which of the following circuit elements is used to 'block' DC in an electronic circuit ?

• A. Resistances
• B. Capacitance
• C. Inductance
• D. Diode

Explanation: A capacitor charges briefly and then blocks steady direct current, while allowing alternating current to pass depending on frequency. A resistor limits current and an inductor tends to oppose changes in current rather than simply block DC.

1869. In a photocell light energy is converted into?

• A. potential energy
• B. chemical energy
• C. heat energy
• D. electrical energy

Explanation: A photocell uses the photoelectric effect to convert incident light into an electrical signal or current. It does not primarily convert light into heat, chemical energy or stored potential energy.

1870. Which gas does a Photocopier machine produce?

• A. Ozone
• B. carbon dioxide
• C. Sulfur dioxide
• D. None of these

Explanation: Photocopiers can produce ozone when high-voltage corona wires ionise oxygen during the electrostatic copying process. Modern machines reduce this by using alternative charging systems and ozone filters.