General Science Questions (MCQs) for Competitive Examinations
General Science Multiple choice questions for GK paper in SSC, NDA, CDS, UPSC, UPPSC and State PSC Examinations. These questions are part of GKToday’s 35000+ MCQs Bank Course in GKToday Android App
11. In which of these transistors, the two segments of n-type semiconductor are separated by a segment of p-type semiconductor?
[A] p-n-p transistor
[B] n-p-n transistor
[C] Both a and b
[D] None
Show Answer
Correct Answer: B [n-p-n transistor]
Notes:
n-p-n transistor :The two segments of n-type semiconductor (emitter and collector) are separated by a segment of p-type semiconductor (base).
12. Which of these is NOT a compound of carbon?
[A] Acetic acid
[B] Chloroform
[C] Caustic Soda
[D] Methane
Show Answer
Correct Answer: C [Caustic Soda]
Notes:
Caustic soda is a compound of sodium where as Acetic acid, Chloroform and Methane are the compounds of carbon.
13. What is an alloy of mercury with some other metal generally known as?
[A] Galinston
[B] Amalgam
[C] Megalium
[D] Yellow metal
Show Answer
Correct Answer: B [Amalgam]
Notes:
Amalgam is the general name given to an alloy of mercury with some other metal. It can be a solid, liquid or a soft paste depending on the composition of the constituents.
14. Which of the following molecules have a T-shape arrangement?
[A] Ozone
[B] Water
[C] Chlorine Trifluoride
[D] Sulphur dioxide
Show Answer
Correct Answer: C [Chlorine Trifluoride]
Notes:
Chlorine trifluoride has 10 electrons around the central chlorine atom. There are five electron pairs arranged in a trigonal bipyramidal shape and two equatorial lone pairs making the final structure T-shaped.
15. What is the length of O-O double bond in an ozone molecule?
[A] 121 pm
[B] 148 pm
[C] 143 pm
[D] 123 pm
Show Answer
Correct Answer: A [121 pm]
Notes:
the length of O=O double bond in an ozone molecule is 121 pm and the length of O-O single bond in an ozone molecule is 148 pm.
16. What are the structures formed by the soap molecules, during cleansing, known as?
[A] Stereates
[B] Esters
[C] Micelles
[D] Tubes
Show Answer
Correct Answer: C [Micelles]
Notes:
The ionic-end of soap dissolves in water while the carbon chain dissolves in oil. The soap molecules form structures called micelles where one end of the molecules is towards the oil droplet while the ionic-end faces outside.
17. Rosalind Franklin contributed into which of the following major breakthroughs of science?
[A] Discovery of Virus
[B] Discovery of Uranium
[C] Discovery of DNA Double Helix
[D] Discovery of Photosynthesis
Show Answer
Correct Answer: C [Discovery of DNA Double Helix]
Notes:
Rosalind Franklin (1920 – 1958) was an English chemist and physicist who contributed to the discovery of the DNA double helix. Her X-ray diffraction image of DNA played an important role in its discovery. She also performed important research into the polio and TMV viruses.
18. An element has only K and L shell and both are full with electrons as per their capacity. What is its atomic number?
[A] 8
[B] 10
[C] 12
[D] 14
Show Answer
Correct Answer: B [10]
Notes:
K – 2 electrons; L-8 electrons so total will be 10.
19. Indicators such as litmus can be used to determine:
- Acidity or alkalinity of a solution
- pH value of a solution
Select the correct option from the codes given below:
[A] Only 1
[B] Only 2
[C] Both 1 & 2
[D] Neither 1 nor 2
Show Answer
Correct Answer: A [Only 1]
Notes:
Common indicators, like litmus, methyl orange and phenolphthalein easily detect whether a solution is acidic or alkaline, but they cannot easily determine how much a given acidic solution is stronger than another acidic solution. It means they cannot really tell us the pH value of different acidic or alkaline solutions. In case of litmus, we cannot tell about pH values of 5, 6 and 7. Similarly, in case of methyl orange pH values between 3 and 8 will not be very accurate.
20. In which of the following hemocaelic body cavity is found?
[A] Cockroach
[B] Lizard
[C] Mosquito
[D] Honeybee
Show Answer
Correct Answer: A [Cockroach]
Notes:
Hemocoelic body cavity is a characteristic of Cockroach.
