A motor car starting from rest, moves with uniform acceleration and attains a velocity of 10 m/s in 5 s. It then moves with uniform velocity and is finally brought to rest in 25 m under uniform retardation. The total distance covered by the car is 225 m. The retardation of the car is ____ m/s2.
The density of a metal block is 2.7 × 103 kg/m3. It will sink in water.
A vehicle of mass 200 kg travelling on a rough horizontal road comes to rest after traveling a distance of 10 m. If the frictional force between the vehicle's tyres and road is 400 N, then the work done by the force on the vehicle is ____ J.
B) – 2000
Using the technique of SONAR, sound pulses are detected after reflection from the bottom of a sea. If the time interval between the emission to the detection of the sound pulses is 5 s, then the depth of the sea is ____ m. ( Speed of sound in water = 1498 m/s)
When equal volumes of liquids X, Y and Z in plates A, B and C are evaporated, it is observed that the liquid in plate B evaporates first followed by C followed by A. We conclude that ____.
A) X is more volatile than Y and Z
B) the boiling point of Y is less than Z
C) the boiling point of Y is more than Z
D) the boiling points of Y and Z are same but that of X is less
We can separate a ____ component from its ____ solute by the method of evaporation.
A) volatile, volatile
B) volatile, non-volatile
C) non-volatile, volatile
D) non-volatile, non-volatile
Mass of 10 moles of CO2 = Mass of ____ .
A) 6.4 moles of C a C2
B) 4.4 moles of CaCO3
C) 5.6 moles of CaO
D) 7.4 moles of Ca(OH)2
The percentages of isotopes 8X16 and 8X18 in a sample, if the average atomic mass of an element X is 16.2 u are ____.
A) 75 and 25
B) 80 and 20
C) 85 and 15
D) 90 and 10
Which among the following is not a characteristic of parenchyma?
A) Present in stem, root, leaves, flowers and fruits.
B) Cells may be oval, round, elongated or polygonal.
C) Dead and thick walled cells.
D) Living cells with dense cytoplasm, small nucleus and a large central vacuole.
Antibiotic penicillin kills bacteria by ____.
A) blocking the respiratory pathway
B) the cell wall
C) blocking the genetic material
D) destroying RNA