IIT JEE प्रश्न और उत्तर का अभ्यास करें

प्र: Three unbiased coins are tossed. What is the probability of getting at most two heads ? 1586 0

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    4/3
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  • 2
    2/3
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  • 3
    3/2
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  • 4
    3/4
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उत्तर : 4. "3/4"
व्याख्या :

Answer: D) 3/4 Explanation: Let S be the sample space.Here n(S)= 23 = 8Let E be the event of getting atmost two heads. Then,n(E) = {(H,T,T), (T,H,T), (T,T,H), (H,H,T), (T,H,H), (H,T,H)}Required probability = n(E)/n(S) = 6/8 = 3/4.

प्र: A jeep travels a certain distance taking 6 hrs in forward journey, during the return journey increased speed 12km/hr takes the times 4 hrs. What is the distance travelled by the jeep is ? 1586 0

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    244 km
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  • 2
    144 km
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    444 km
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  • 4
    344 km
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उत्तर : 2. "144 km"
व्याख्या :

Answer: B) 144 km Explanation: Given a jeep travels a certain distance taking 6 hrs in forward journeyDuring the return journey, it takes 4 hrs with an increased speed 12 km/hrLet 'x' be the distance.Now, speed is given by distance/time.Here the difference between both speeds = 12  x4 - x6 = 12  3x - 2x12 = 12   => x = 144 km   Therefore, the distance travelled by the jeep in forward or return journey is x = 144 km.

प्र: Which colony was farthest north? 1586 0

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    Massachusetts
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    Virginia
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    Georgia
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  • 4
    New Hampshire
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उत्तर : 1. "Massachusetts"
व्याख्या :

Answer: A) Massachusetts Explanation: There are 13 colonies and are ruled by England.   The farthest north colony - Massachusetts The farthest south colony - Georgia The oldest colony - Virginia The colony between the 2 parts of Massachusetts - New Hampshire

प्र: What is common between Aerobic and Anaerobic Respiration? 1585 0

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    Krebs cycle
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    Glycolysis
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    Electron transport chain
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    All the above
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उत्तर : 2. "Glycolysis"
व्याख्या :

Answer: B) Glycolysis Explanation: Glycolysis is common between Aerobic and Anaerobic Respiration.   Cellular respiration is the process by which glucose is broken down to form ATP molecules, which act as carriers of cellular energy. The first phase is called glycolysis and is common to both aerobic (respiration in the presence of oxygen) and anaerobic (respiration in the absence of oxygen) respiration.   During glycolysis, glucose is split to forms two pyruvate molecules and 2 molecules of ATP. This occurs in the cytoplasm of the cell.   If oxygen in present, the pyruvate molecules will be used in the Krebs cycle, to yield more ATP molecules. If oxygen is absent, the pyruvate is converted into lactic acid, or ethanol and carbon dioxide, in animals or plants, respectively.

प्र: How does molecular shape affect polarity? 1585 0

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उत्तर :
व्याख्या :

Polarity ::  The polarity of a molecule defines its other physical properties such as melting point, boiling point, surface tension, vapor pressure etc... Simply, polarity occurs when the electron distribution in a molecule is asymmetric. This results in a net dipole moment in the molecule. One end of the molecule is charged negative while the other gets a positive charge.   The polarization of a molecule greatly depends on the shape of the molecule. A diatomic molecule like HF mentioned above has no issue of shape. The net dipole moment is only due to the uneven distribution of electrons between the two atoms. However, when there are more than two atoms involved in making a bond, there are many complexities.   The water molecule is of bent shape. Therefore, when the two pair of electrons shared by oxygen with two hydrogen atoms is pulled towards oxygen, the net dipole moment results in the direction of the oxygen atom. There is no other force to cancel out the resultant dipole moment. Hence, the water molecule is highly polar.   Ammonia molecule is of a pyramid shape and the electronegative N atom pulls the electrons towards itself. The three N-H bonds are not in the same plane; hence the dipole moments created do not get canceled out. This makes ammonia a polar molecule.   However, the dipole moments sometimes get canceled due to the shape of the molecules, making the molecule non-polar. Carbon dioxide is such a molecule.

प्र: Which ocean surrounds Antarctica? 1584 0

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    Atlantic ocean
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    Indian ocean
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    Pacific ocean
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    Southen ocean
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उत्तर : 4. "Southen ocean"
व्याख्या :

Answer: D) Southen ocean Explanation: Antarctica is surrounded on all sides by water. The Indian, Pacific and Atlantic Oceans surround it on all sides. These three Oceans all meet at Antarctica. The three oceans are collectively called the Southern Ocean. This is the area located south of 50° latitude.

प्र: What is the Capital city of Peru? 1583 0

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    Sucre
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    Manama
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    Lima
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    Bogota
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उत्तर : 3. "Lima"
व्याख्या :

Answer: C) Lima Explanation: Lima is the Capital of Peru and its Currency is Sol.

प्र: What is the maximum velocity with which a body of mass 'm' must enter a vertical loop of radius 'R'so that it can complete the loop? 1583 0

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    0
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    gR
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    2gR
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    5gR
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उत्तर : 4. "5gR"
व्याख्या :

Answer: D) D Explanation: To complete the vertical loop, the minimum speed required at the lowest point  = 5gR.

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