20000+ Important MCQs for AIR FORCE

Explanation :
Dilute sulfuric acid {H2 SO4} serves as the electrolyte in a lead storage battery. The electrodes of the cells in a lead storage battery consist of lead grids. The openings of the anodic grid is filled with spongy (porous) lead. The openings of the cathodic grid is filled with lead dioxide {PbO2}.

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ssc Online Exam general science mcq questions and answers for competitive exams :: :: Home general science mcq questions and answers for competitive exams / Questions and Answers 4081. The angle in which a cricket ball should be hit to travel max. horizontal distance is: A 60° with horizontal B 30° with horizontal C 15° with horizontal D 45° with horizontal View Answer Discuss in Forum Answer & Explanation Answer : Option D Explanation : 45° with horizontal.This has to do with the equation of a parabola or trajectory which is z = (tanq)x – q 2 (cos) q x 2. We can see that if the ball is fired at a 45 degree angle from the ground, the horizontal distance will be a maximum. 4082. Which among the given is a radioactive element - A Chromium B Cobalt C Uranium D Argon View Answer Discuss in Forum Answer & Explanation Answer : Option C Explanation : Uranium.Uranium (U) is a naturally occurring radioactive element. One of its isotopes, uranium-235, is the only naturally occurring isotope capable of sustaining a nuclear fission reaction. Its nucleus is unstable, so the element is in a constant state of decay, seeking a more stable ar- rangement.In fact, uranium was the element that made the discovery of radioactivity possible.

Explanation :
ssc Online Exam general science mcq questions and answers for competitive exams :: :: Home general science mcq questions and answers for competitive exams / Questions and Answers 4081. The angle in which a cricket ball should be hit to travel max. horizontal distance is: A 60° with horizontal B 30° with horizontal C 15° with horizontal D 45° with horizontal View Answer Discuss in Forum Answer & Explanation Answer : Option D Explanation : 45° with horizontal.This has to do with the equation of a parabola or trajectory which is z = (tanq)x – q 2 (cos) q x 2. We can see that if the ball is fired at a 45 degree angle from the ground, the horizontal distance will be a maximum. 4082. Which among the given is a radioactive element - A Chromium B Cobalt C Uranium D Argon View Answer Discuss in Forum Answer & Explanation Answer : Option C Explanation : Uranium.Uranium (U) is a naturally occurring radioactive element. One of its isotopes, uranium-235, is the only naturally occurring isotope capable of sustaining a nuclear fission reaction. Its nucleus is unstable, so the element is in a constant state of decay, seeking a more stable ar- rangement.In fact, uranium was the element that made the discovery of radioactivity possible. 4083. Synthetic detergents are prepared from A glycerides B potassium salts of higher fatty-acids C hydrocarbons of petroleum D sodium salts of higher fattyacids View Answer Discuss in Forum Answer & Explanation Answer : Option C Explanation : hydrocarbons of petroleum.Synthetic detergents are prepared from hydrocarbons of petroleum. Calcium & magnesium salts of detergents are soluble in water. They are sodium salts of a long chain benzene sulphonic acids or sodium salts of long chain alkyl hydrogen sulphates. So cleansing action of detergents remain unaffected in hard water.

Explanation :
ssc Online Exam general science mcq questions and answers for competitive exams :: :: Home general science mcq questions and answers for competitive exams / Questions and Answers 4081. The angle in which a cricket ball should be hit to travel max. horizontal distance is: A 60° with horizontal B 30° with horizontal C 15° with horizontal D 45° with horizontal View Answer Discuss in Forum Answer & Explanation Answer : Option D Explanation : 45° with horizontal.This has to do with the equation of a parabola or trajectory which is z = (tanq)x – q 2 (cos) q x 2. We can see that if the ball is fired at a 45 degree angle from the ground, the horizontal distance will be a maximum. 4082. Which among the given is a radioactive element - A Chromium B Cobalt C Uranium D Argon View Answer Discuss in Forum Answer & Explanation Answer : Option C Explanation : Uranium.Uranium (U) is a naturally occurring radioactive element. One of its isotopes, uranium-235, is the only naturally occurring isotope capable of sustaining a nuclear fission reaction. Its nucleus is unstable, so the element is in a constant state of decay, seeking a more stable ar- rangement.In fact, uranium was the element that made the discovery of radioactivity possible. 4083. Synthetic detergents are prepared from A glycerides B potassium salts of higher fatty-acids C hydrocarbons of petroleum D sodium salts of higher fattyacids View Answer Discuss in Forum Answer & Explanation Answer : Option C Explanation : hydrocarbons of petroleum.Synthetic detergents are prepared from hydrocarbons of petroleum. Calcium & magnesium salts of detergents are soluble in water. They are sodium salts of a long chain benzene sulphonic acids or sodium salts of long chain alkyl hydrogen sulphates. So cleansing action of detergents remain unaffected in hard water. 4084. When Arsenic atoms are added to Germanium lattice, it becomes a/an A Insulator B Extrinsic semiconductor C Intrinsic semiconductor D Superconductor View Answer Discuss in Forum Answer & Explanation Answer : Option B Explanation : When a pentavalent (donor) impurity, like arsenic, is added to germanium, it will form covalent bonds with the germanium atoms, leaving 1 electron relatively free in the crystal structure. Pure germanium may be converted into an N-type semiconductor by 'doping' it with any donor impurity having 5 valence electrons in its outer shell. Semiconductors which are doped in this manner - either with N- or P-type impurities - are referred toas EXTRINSIC semiconductors.

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Explanation :
H2 SO4.Sulfuric acid is used as a catalyst for refining & for producing alkylate, an essential component of highoctane fuel. The hydrocarbon molecules are reformed into more complex molecules with a higher octane rating value.

Explanation :
Cadmium.Cadmium is a soft, malleable, ductile, bluish-white divalent metal. Unlike other metals, cadmium is resistant to corrosion & as a result it is used as a protective layer when deposited on other metals. It is similar in many respects to zinc but forms complex compounds. As a bulk metal, cadmium is insoluble in water & is not flammable; however, in its powdered form it may burn & release toxic fumes. Cadmium occurs as a minor component in most zinc ores & so is a byproduct of zinc production. It was used for a long time as a pigment & for corrosion resistant plating onsteel while cadmium compounds were used to stabilize plastic. With the exception of its use in nickel–cadmium batteries & cadmium telluride solar panels, the use of cadmium is generally decreasing. These declines have been due to competing technologies, cadmium's toxicity in certain forms & concentration & resulting regulations.

Explanation :
decibel.Noise pollution refers to any unpleasant, damaging or irritating noise that has the potential to harm people, wildlife or the environment. A sound can also be measured by its pitch, which is the frequency of sound vibrations per 2nd. The decibel (dB) is the main unit used to measure the intensity or loudness of sounds.