Answer: A) atrial depolarization Explanation: The P wave in the ECG represents atrial depolarization, which results in atrial contraction, or atrial systole. The P wave is a summation wave generated by the depolarization front as it transits the atria.

Answer: B) 24 kmph Explanation: Total time taken = k/40 + 2k/20 hours = 5k/40 = k/8 hours Average speed = 3k/(k/8) = 24 kmph.

Answer: B) 30 mts Explanation: The cow can graze an area of 2826 sq.m i.e it is able to cover area of circle of 2826 sq.m   Therefore, πr2 =2826r2 =(2826×7/22) = 899.18 = 900r = 30 m.   Therefore, the radius of the circle implies the length of the rope = 30 mts.

Answer: C) 70000 Explanation: 112 × 54112 × 1024= 112 × 1000024= 1120000/16 = 70,000.

Answer: C) 7 & 24 Explanation: 7 boxes & 24 Balls.Let, n = No. of boxes ; m = No. of fruits3n+3 = m---------->(1)4(n-1)= m---------->(2)=>4n-4 = 3n+3;=>4n-3n = 4+3n = 7Put n=7 in eqn(1)=> 3(7)+3 = m21+3 = mm = 24; Number of boxes = 7 and fruits = 24

Answer: D) 3 : 2 Explanation: Let the speeds of the two trains be x m/sec and y m/sec respectively. Then, length of the first train = 27 x meters, and length of the second train = 17 y meters. (27 x + 17 y) / (x + y) = 23 => 27 x + 17 y = 23 x + 23 y => 4 x = 6 y => x/y = 3/2.

Answer: B) 4 % Explanation: Imension of the duster is assumed as 5x5x7 cm3 Volume of the duster below the water layer= volume of water increased= πxrxrxh = 3.14×52×2.14 ≈ 168 cm3 Total volume of the duster = 5×5×7 = 175 cm3 Percentage of the duster part below the layer = 168×100/175 = 96% Percentage of the duster part above the layer = 4%

Answer: A) X Explanation: The logic in the given puzzle is  Addition of numeric values of corresponding letters in the first three figures gives respective corresponding letter in fourth figure.  i.e, A = 1 , W = 23 , B = 2 => 2 + 1 + 23 =26 = 'Z' Similarly, L = 12, K = 11 , A = 1 => 1 + 11 + 12 = 24 = 'X' Here the missing letter is 'X'.