Class 11th

This is a multiple choice answer as classified in NCERT Exemplar

Option (i).  16 grams of gas and

(iv). 11.2 litres of gas 

1 mole of dioxygen at STP  occupies   =  22.4 L    

molar mass of dioxygen  =   32 g 

contain  6.023*10²³ molecules of  oxygen gas 

This is a Multiple Choice Questions type Questions as classified in NCERT Exemplar

Answer- c

Explanation- change in momentum $?p$ =- [0.9? +1.2? ]

Magnitude = $\sqrt[]{{0.9}^2+{1.2}^2}$

$=\sqrt[]{0.81+1.44}=$ 1.5 kg m s^-1       

This is a Multiple Choice  type Questions as classified in NCERT Exemplar

Answer- c

Explanation- given u= (3? +4? )m/s

And v= - (3? +4? )m/s, and mass of ball is 150g=0.15kg

Change in momentum = final momentum – initial momentum

 = mv-mu

= m (v-u) = 0.15 [- (3? +4? )- (3? +4? )]

= - [0.15 $*6i+0.15*8j$ ]

= - [0.9? +1.2? ]

$?$ P =- [0.9? +1.2? ]

This is a multiple choice answer as classified in NCERT Exemplar

Option (ii). Complete disorder of molecules and

(iii). Random motion of molecules 

In a gaseous state of matter, molecules are arranged in complete disorder and  they move in random motion in all directions.

This is a Multiple Choice type Questions as classified in NCERT Exemplar

Answer-b

Explanation- to solve this question we have to apply newton's law of motion, in terms of force and change in momentum.

as we know F= dp/dt

As body moving uniform velocity so dp= 0

So F=0

As all part of scale is moving with uniform velocity and total force is zero . hence torque will also be zero.

This is a multiple choice answer as classified in NCERT Exemplar

Option (ii).  Decreases

When the temperature increases, kinetic energy of the molecule increases which leads to decrease in the intermolecular forces and hence, decreases the surface tension. 

This is a Multiple Choice Type Questions as classified in NCERT Exemplar

Answer- c

Explanation- in a uniform translatory motion, all parts of the ball have the same velocity in magnitude and direction and this velocity is constant . in this situation body A will be in translatory motion.

This is a multiple choice answer as classified in NCERT Exemplar

Option (iii) Decrease 

The increase in temperature increases the kinetic energy which can overcome intermolecular forces of attraction due to which the viscosity decreases and the liquid starts flowing. 

This is a multiple choice answer as classified in NCERT Exemplar

Option (i). B only 

For all ideal gas PV = constant. Only B has no change with the change in PV, so only line B represents the curve of ideal gas.

This is a multiple choice answer as classified in NCERT Exemplar

option (i). Shimla 

The temperature at which the liquid boils when the vapour pressure becomes equal to the atmospheric pressure  is known as the boiling point of the liquid. When the  atmospheric pressure is low, the boiling point of the liquid will be low. As Shimla has the lowest atmospheric pressure, it will boil first.