The correct answers with their questions numbers.
1 = A , 2 = C , 3 = B , 4 = A , 5 = D , 6 = B , 7 = A , 8 = B , 9 = C , 10
= C , 11 = B , 12 = C , 13 = A , 14 = B , 15 = B , 16 = C , 17 = A
Physics full notes of class 11 ch6 McQs end.
Question 1 Answer: Smoke rises in a chimney faster when a breeze is
blowing. The Bernoullis principle plays a vital role in this process. As the
wind blows across the top of a chimney , the pressure is less there than the
pressure inside the house. Thus the air and smoke are psuhed up the chimney
faster when a breeze is blowing.
Question 2 Answer: Many trailer trucks use wind deflectors on the top of
their cabs to reduce air resistance. Using these deflectors , the workdone
against air resistance is reduced significantly. In this way the consumption of
fuel is minimized.
Question 3 Answer: The wing of an aeroplane is design in such a away that
the velocity of the air flow is higher above its surface as compared to its
lower surface. According to Bernoullis principle the pressure of a fluid
decreases in the region where the speed of air is higher. Therefore the
pressure below the wing is greater due to lower velocity of air and pressure
is smaller above the wing due to greater velocity of air. In this way a
pressure difference is developed which causes a net upwards (lift) force
acting on the wing of aeroplane.
Question 4 Answer: When a fast moving train passes a man standing on the
platform at rest, the air between train and person also moves with greater
speed. According to Bernoullis principle the pressure decrease in the region
where the air is flowing with higher speed. During this time , the pressure
behind the person is maximum which may push him towards the low pressure
region , towards the train.
Question 5 Answer: When we blow over the top surface of the sheet of
paper the speed of air increases at the top. According to Bernoullis principle
the pressure dcreases in the region where air flows with higher speed. Thus
the pressure at the top of sheet the pressure is maximum. This difference in
pressure provides a net upwards force due to which the sheet of paper rises
up in the air.
Question 6 Answer: When we turn on our shower water at full speed the
water from inside flows out at high speed. According to Bernoullis principle
the pressure decreases in the region where the fluid flows with high speed.
Thsu the pressure inside decreases and as a result the shower curtain is
pushed inwards due to outside maximum pressure.
Question 7 Answer: When air is blown from ahair dryer over the top of a
ping-pong ball, the speed of air above the ball increases. According to
Bernoullis principle the pressure decreases in the region where speed of air
increases. Thus the pressure of air above the ball is reduced while the
pressure below the ball is maximum. In this way a difference in pressure is
developed which provides an upwards force due to which the ball is prevented
from falling and thus remains in state of equilibrium.
Question 8 Answer: When a fast moving baseball moves in such a way that it
spins as well as moves forward, the velocity of ball increases due to spin due
to which the pressure in that region dcreases , While the pressure on the
otherside of the ball is maximum due to which that is deflected from its
path. In this way an extra curvature is given to the ball which is known as
Question 10 Answer: When a liquid passes through a pipe and its rate of
influx is equal to the rate of efflux then such liquid have steady state flow.
The liquid will be incompressible and will have uniform density.
Physics full notes of class 11 ch6 short questions end.