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.

Answer: C) 1001 Explanation: Here by trial and error method, we can obseve that 404404 = 404 x 1001; 415415 = 415 x 1001, etc. So, any number of this form is divisible by 1001.

Answer: B) 18.75% Explanation: Given that to find 15 of 80 => What % of 80 is 15 Let it be 'p' => p% of 80 = 15 => p x 80100 = 15⇒p = 15 x 10080⇒p = 150080 = 18.75   Therefore, 15 is 18.75% of 80 => 18.75% of 80 = 15   Example:: Now, in the similar way we can find 15% of 80 =? => 15x80/100 = p => p = 4 x 3 = 12   Therefore, 15% of 80 = 12

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.

Answer: A) 14/33 Explanation: Total number of chairs = (3 + 5 + 4) = 12. Let S be the sample space. Then, n(s)= Number of ways of picking 2 chairs out of 12 = 12×11/2×1 = 66 Let n(E) = number of events of selecting 2 chairs for selecting no white chairs. => 8C2 = 8×7/2×1 = 28 Therefore required probability = 28/66 = 14/33.

Answer: D) 35 Explanation: Let the total applicants be 100   Then, 20% got 85 marks i.e 20 x 85 = 1700   and 25% got 95 marks  i.e 25 x 95 = 2375   Now, the remaining applicants are 55 and let the average marks scored by them be x.   Therefore, 2375 + 1700 + 55x  =  60×100  6000 - 4075 = 55x 55x=1925 x=35.

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.

Answer: D) 16.38 Explanation: Given, Manideep purchases 30kg of barley at the rate of 11.50/kg nad 20kg at the rate of 14.25/kg. Total cost of the mixture of barley = (30 x 11.50) + (20 x 14.25) => Total cost of the mixture = Rs. 630 Total kgs of the mixture = 30 + 20 = 50kg Cost of mixture/kg = 630/50 = 12.6/kg To make 30% of profit => Selling price for manideep = 12.6 + 30% x 12.6 => Selling price for manideep = 12.6 + 3.78 = 16.38/kg.