Tag: science & technology

Quizzes (551) Questions (11015)

Questions Related to science & technology

Multiple choice general knowledge science & technology

WHICH IS THE MAJORITY CARRIER IN N TYPE SEMICONDUCTOR??

  1. HOLES

  2. ELECTRONS

  3. BOTH

  4. NONE OF THE ABOVE
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In N-type semiconductors, the majority charge carriers are electrons because these materials are doped with donor atoms that contribute extra electrons. Holes are the minority carriers in N-type material. This is fundamental to understanding how semiconductor devices like diodes and transistors work.

Multiple choice general knowledge science & technology

BJT IS

  1. 2 TERMINAL DEVICE

  2. 3 TERMINAL DEVICE

  3. 4 TERMINAL DEVICE

  4. NONE OF THE ABOVE
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

BJT (Bipolar Junction Transistor) has three terminals: emitter, base, and collector. It is called bipolar because it uses both electrons and holes as charge carriers. A 2-terminal device would be a diode, and 4-terminal devices are uncommon in basic electronics.

Multiple choice general knowledge science & technology

What was CDMA technology's origin ?

  1. USA

  2. Russia

  3. Australia

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

CDMA (Code Division Multiple Access) technology was developed in the United States by Qualcomm and other researchers in the late 1980s and early 1990s. It became a key part of American telecommunications standards, particularly for 2G and 3G mobile networks. Russia, Australia, and Germany used GSM as their primary early digital mobile technology.

Multiple choice general knowledge science & technology

BJT IS BIPOLAR DEVICE

  1. True

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

BJT is indeed a bipolar device because it uses both majority and minority charge carriers (electrons and holes) for current flow. This distinguishes it from FETs (Field Effect Transistors) which are unipolar devices using only one type of charge carrier. The 'bipolar' name directly refers to this dual-carrier operation.

Multiple choice general knowledge science & technology

Our earth orbits around the sun. How long does one complete orbit of the earth around the sun take?

  1. Less than 365 1/4 days

  2. Exactly 365 1/4 days

  3. More than 365 1/4 days

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

One orbit around the sun (a tropical year) takes approximately 365.2422 days, which is slightly less than 365 1/4 (365.25) days. The difference is why our calendar skips leap years on century years not divisible by 400. The 365 1/4 approximation was used in the Julian calendar but was slightly too long.

Multiple choice general knowledge science & technology

The earth not only orbits around the sun, but also spins round her axis. How long does one complete turn of the earth round her axis take?

  1. Less than 24 hours

  2. Exactly 24 hours

  3. More than 24 hours

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Earth's actual rotation period (sidereal day) is approximately 23 hours, 56 minutes, and 4 seconds, which is less than 24 hours. The 24-hour solar day is slightly longer because Earth must rotate a bit extra to face the sun again due to its orbital motion. This is why stars rise about 4 minutes earlier each night.

Multiple choice general knowledge science & technology

In our western calendar there are years of 365 days and leap years of 366 days. How often is it a leap year in our calendar?

  1. Exactly once in every 4 years

  2. More than once in every four years

  3. Less than once in every four years

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Leap years occur less often than once every 4 years because century years (1700, 1800, 1900) are NOT leap years unless divisible by 400 (1600, 2000). This Gregorian calendar rule averages to 97 leap days in 400 years, not 100. The answer 'less than once in every 4 years' correctly captures this nuance.

Multiple choice general knowledge science & technology

The calendar that we use has a name. What is the name of our western calendar?

  1. Julian calendar

  2. Gregorian calendar

  3. Roman calendar

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

The Gregorian calendar is the western calendar used globally today, introduced by Pope Gregory XIII in 1582 to reform the Julian calendar. The Julian calendar was its predecessor but had too many leap years. The Roman calendar was even earlier and less sophisticated. There is no 'International calendar' as a formal name.

Multiple choice general knowledge science & technology

The year is divided into four seasons: spring, summer, autumn and winter. On the northern hemisphere it is summer when it is winter on the southern hemisphere, and the other way around. Which of the following sentences is true?

  1. The summer on the northern hemisphere is longer than the summer on the southern hemisphere

  2. The summer on the northern hemisphere is shorter than the summer on the southern hemisphere

  3. The summer on the northern hemisphere is as long as the summer on the southern hemisphere

  4. None of the above
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Northern hemisphere summer is slightly longer than southern hemisphere summer. This is because Earth is closer to the sun (perihelion) in January, during southern summer, making it move faster and shortening that season. Conversely, Earth is farther (aphelion) in July during northern summer, moving slower and lengthening it. The difference is several days.