Tag: science & technology

Quizzes (551) Questions (11015)

Questions Related to science & technology

Multiple choice general knowledge science & technology

A semiconductor has electrical properties between metals and insulators but similar to all materials, its resistivity will decrease and will conduct more electricity as its temperature is increased?

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Semiconductors exhibit a negative temperature coefficient of resistance - their resistivity decreases as temperature increases. This is because higher temperature provides more thermal energy, exciting more electrons into the conduction band. This behavior is fundamentally different from metals, whose resistivity increases with temperature due to increased phonon scattering.

Multiple choice general knowledge science & technology

TNT2, 4,6-Trinitrotoluene, commonly known as TNT, is a what, odourless solid that does not occur naturally in the environment?

  1. red

  2. brown

  3. green

  4. yellow
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

TNT (trinitrotoluene) is a yellow, odorless solid in its pure form. The 'trinitrotoluene' in the question appears to be a typo. TNT is an explosive compound that does not occur naturally and must be synthesized. Its characteristic pale yellow color is a well-known physical property.

Multiple choice general knowledge science & technology

ATP needs to be regenerated continuously by the recombining of ADP and?

  1. N

  2. P

  3. O

  4. R
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

ATP (adenosine triphosphate) is regenerated from ADP (adenosine diphosphate) by adding an inorganic phosphate group (Pi). This process is catalyzed by ATP synthase during cellular respiration and photosynthesis. The 'P' in the question refers to phosphorus/phosphate, completing the ADP + P → ATP cycle.

Multiple choice general knowledge science & technology

Aluminum oxide is an electrically insulating material with high resistivity that increases with purity With its high corrosion resistance, it does not wear easily, even against strong what?

  1. acid

  2. heat

  3. wind

  4. rain
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Aluminum oxide (Al₂O₃) exhibits exceptional chemical inertness and high corrosion resistance, particularly against acids. This property, combined with its electrical insulation and high wear resistance, makes it valuable in applications like chemical processing equipment, crucible linings, and protective coatings. The sentence structure is awkward but the factual content is correct.

Multiple choice general knowledge science & technology

In the n-type doping, atoms that have how many more valence electron than the semiconductor atom are added to the semiconductor?

  1. four

  2. three

  3. two

  4. one
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In n-type doping, donor atoms with one MORE valence electron than the semiconductor atom are added. For example, in silicon (4 valence electrons), phosphorus (5 valence electrons) is added as a donor. The extra electron becomes free to conduct current, creating negative charge carriers. This is why it's called 'n-type' (negative-type).