Free Technology and Energy MCQs with Answers

71. Fan was invented by___________?

• A. Arthur Schimit
• B. Alfered Nobel
• C. Skaats Wheeler
• D. None of these

Explanation: The electric fan is credited to Schuyler Skaats Wheeler, who developed an early electric fan in the 1880s. Option c contains his name with a spelling error but clearly identifies him.

72. Who invented steamboat?

• A. James Watt
• B. Robert Fluton
• C. Frank Whittle
• D. George Stephenson

Explanation: Robert Fulton developed the commercially successful steamboat Clermont in 1807. James Watt improved the steam engine, but he did not invent the steamboat.

73. Chronometer is invented by________?

• A. Robert Fulton
• B. Nikola Tesla
• C. Martin Cooper
• D. John Harrison

Explanation: John Harrison developed the marine chronometer in the 18th century, solving the problem of determining longitude at sea. The other names are associated with inventions such as the steamboat, electrical systems and the mobile phone.

74. Black gold is an oil; Black diamond is_________?

• A. Copper
• B. Iron
• C. Coal
• D. Wood

Explanation: Coal is called black diamond because of its black appearance and high economic value as a fuel. Oil is similarly called black gold because it is commercially valuable.

75. Silicon is an example of _________?

• A. No-conductor
• B. Semiconductor
• C. Super Conductor
• D. None of these

Explanation: Silicon is a semiconductor because its electrical conductivity lies between that of conductors and insulators and can be controlled by doping. This property makes it central to electronic chips and solar cells.

76. Who invented bifocal eyeglasses?

• A. Ibn-e-Haitem
• B. Benjamin Franklin
• C. Archemedes
• D. None

Explanation: Benjamin Franklin invented bifocal spectacles in the 18th century by combining lenses for distance and near vision in one pair. Ibn al-Haytham made important contributions to optics but did not invent bifocals.

77. Which of the following mixture of gases is required in gas welding?

• A. Oxygen and ethylene
• B. Oxygen and hydrogen
• C. Acetylene and oxygen
• D. Acetylene and hydrogen

Explanation: Gas welding commonly uses acetylene burned in oxygen because the oxyacetylene flame reaches a very high temperature. Hydrogen and oxygen can burn, but they are not the standard gas-welding mixture intended here.

78. Who invented the first battery?

• A. Alessandro volta
• B. Tim Berner
• C. Rob Stothard
• D. Georges Leclanche

Explanation: Alessandro Volta invented the voltaic pile in 1800, widely regarded as the first true battery. The unit of electric potential, the volt, is named after him.

79. Very small time intervals are accurately measured by the___________?

• A. Pabsars
• B. White dwarfs
• C. Atomic Clocks
• D. None of these

Explanation: Atomic clocks measure time using the highly stable frequency of atomic transitions, especially in cesium or rubidium atoms. Their stability allows extremely small time intervals to be measured accurately.

80. Who invented Logarithm Tables?

• A. John Napier
• B. John Doe
• C. John Harrison
• D. John Douglas

Explanation: John Napier introduced logarithms and published the first logarithm tables in 1614. These tables transformed difficult multiplication and division into simpler addition and subtraction.