Free Technology and Energy MCQs with Answers

61. Optic fibers are mainly used for which of the following:

• A. Communication
• B. Weaving
• C. Food indudtry
• D. None of these

Explanation: Optical fibres transmit information as pulses of light with low signal loss, so they are widely used in telephone, internet, and cable communication. Their main purpose is not weaving or food processing.

62. The first cloned animal was____________?

• A. Goat
• B. Cow
• C. Rat
• D. Sheep

Explanation: Dolly, a sheep, was the first mammal cloned from an adult somatic cell, making sheep the standard answer in general science MCQs. Earlier experiments cloned embryos and amphibians, so the wording is simplified.

63. Electric motor was invented by __________ ?

• A. Michael Faraday
• B. Oliver Evans
• C. Thomas Edison
• D. Horace Day

Explanation: Michael Faraday demonstrated an early electric motor in 1821 by converting electrical energy into continuous mechanical motion. His work was based on the interaction between electric current and a magnetic field.

64. Medium which sends signal from source to destination is known as ________ ?

• A. Transmitter
• B. Transmission channel
• C. Receiver
• D. Hardware

Explanation: A transmission channel is the medium or path that carries a signal from its source to its destination. A transmitter sends the signal, while a receiver accepts it.

65. The gas usually filled in the electric bulb is___________?

• A. Nitrogen
• B. Hydrogen
• C. Carbon dioxide
• D. Oxygen

Explanation: Traditional incandescent bulbs are filled with nitrogen or another inert gas to reduce evaporation and oxidation of the hot tungsten filament. Nitrogen is the intended answer among these choices, although argon is also widely used.

66. Transistor is a device that convert weak signal into__________?

• A. small signal
• B. strong signal
• C. both
• D. none

Explanation: A transistor can amplify a weak electrical signal, producing a stronger version of the same signal. It can also act as a switch, but amplification is the function intended here.

67. Which of the following invention is oldest ?

• A. Clock
• B. Microscope
• C. Barometer
• D. Cycle

Explanation: Clocks, including ancient sundials and water clocks, were developed long before the microscope, barometer, or bicycle. Thus, the clock is the oldest listed invention.

68. Substance whose atoms can be split are known as __________ materials.

• A. Fusionable
• B. Fissionable
• C. Combustible
• D. None of these

Explanation: Fissionable materials contain atoms whose nuclei can split in a nuclear fission reaction, releasing energy and more neutrons. Combustible materials merely burn through chemical reactions.

69. Transistors do not need a warm up period because they have no ?

• A. Plate
• B. Grid
• C. Filament
• D. None of above

Explanation: Unlike vacuum tubes, transistors have no heated filament or cathode that must reach operating temperature. Their semiconductor action begins without a warm-up period.

70. What is the name of the gas used in an air conditioner?

• A. Ammonia
• B. Nitrous oxide
• C. Freon
• D. CO2Educational Resources

Explanation: Freon was a common name for chlorofluorocarbon refrigerants used in air conditioners. Many Freons were phased out because they damage the ozone layer, but the historical MCQ answer remains Freon.