Question Text
Question 2 :
Assertion: Dust particles generally settle down in a closed room.
Reason: The terminal velocity is inversely proportional to the square of their radii.
Question 3 :
The surface tension of soap solution is $0.03 {N}/{m}$. The work done in blowing to from a soap bubble of surface area $40{ cm }^{ 2 }$, (in $J$), is
Question 4 :
If two soap bubbles of equal radii $r$ coalesce then the radius of curvature of interface between two bubbles will be<br>
Question 5 :
Assertion: The upper surface of the wings of an aeroplane is made convex<br/>Reason: The air current at the top will have greater velocity and thus pressure at the bottom will be greater than at the top
Question 6 :
A copper ball of radius $r$ is moving with a uniform velocity $v$ in the mustard oil and the dragging force acting on the ball is $F$. The dragging force on the copper ball of radius $2r$ with uniform velocity $2v$ in the mustard oil is
Question 7 :
The viscous force acting on a body falling under gravity in a viscous fluid will be<br>
Question 8 :
The type of braking system referred to as power brake makes use of<br/>
Question 9 :
The work done in blowing a soap bubble of radius $r$ of the solution of surface tension $T$ will be<br/>
Question 10 :
The surface tension of a soap solution is $2*10^{-2}N/m$. To blow a bubble of radius $1 cm$, the work done is<br>
Question 11 :
A tube one metre long is filled with liquid of mass $1\space kg$. The tube is closed at both the ends and is revolved about one end in a horizontal plane at $2\space rev/s$. The force experienced by the lid at the other lid is
Question 12 :
What is ratio of surface energy of $1$ small drop and $1$ large drop, if $1000$ small drops combined to form $1$ large drop<br>
Question 14 :
The gale blows over a house. The force due to gale on the roof is:-
Question 15 :
Assertion: Sudden fall of pressure at a place indicates storm<br/>Reason: Air flows from higher pressure to lower pressure.