143118 A boy can reduce the pressure in his lungs to $750 \mathrm{~mm}$ of mercury. Using a straw he can drink water from a glass upto the maximum depth of (atmospheric pressure $=760 \mathrm{~mm}$ of mercury; density of mercury $=13.6 \mathrm{gcm}^{-3}$ )

143119 The area of cross-section of one limb of an $U$ tube is twice that of other. Both the limbs contain mercury at the same level. Water is poured in the wider tube so that mercury level in it goes down by $1 \mathrm{~cm}$. The height of water column is (density of water $=10^{3} \mathrm{~kg} \mathrm{~m}^{-3}$, density of mercury $=13.6 \times 10^{3} \mathrm{~kg} \mathrm{~m}^{-3}$ )

143120 The height of the dam, in a hydroelectric power station is $10 \mathrm{~m}$. In order to generate $1 \mathrm{MW}$ of electric power, the mass of water (in $\mathrm{kg}$ ) that must fall per second on the blades of the turbines is

143121 What is the velocity $v$ of a metallic ball of radius $r$ falling in a tank of liquid at the instant when its acceleration is one-half that of a freely falling body? (The densities of metal and of liquid are $\rho$ and $\sigma$ respectively, and the viscosity of the liquid is $\eta$ ):

143122 Radius of an air bubble at the bottom of the lake is $r$ and it becomes $2 r$ when the air bubble rises to the top surface of the lake. If $P \mathrm{~cm}$ of water be the atmospheric pressure, then the depth of the lake is:

143118 A boy can reduce the pressure in his lungs to $750 \mathrm{~mm}$ of mercury. Using a straw he can drink water from a glass upto the maximum depth of (atmospheric pressure $=760 \mathrm{~mm}$ of mercury; density of mercury $=13.6 \mathrm{gcm}^{-3}$ )

143119 The area of cross-section of one limb of an $U$ tube is twice that of other. Both the limbs contain mercury at the same level. Water is poured in the wider tube so that mercury level in it goes down by $1 \mathrm{~cm}$. The height of water column is (density of water $=10^{3} \mathrm{~kg} \mathrm{~m}^{-3}$, density of mercury $=13.6 \times 10^{3} \mathrm{~kg} \mathrm{~m}^{-3}$ )

143120 The height of the dam, in a hydroelectric power station is $10 \mathrm{~m}$. In order to generate $1 \mathrm{MW}$ of electric power, the mass of water (in $\mathrm{kg}$ ) that must fall per second on the blades of the turbines is

143121 What is the velocity $v$ of a metallic ball of radius $r$ falling in a tank of liquid at the instant when its acceleration is one-half that of a freely falling body? (The densities of metal and of liquid are $\rho$ and $\sigma$ respectively, and the viscosity of the liquid is $\eta$ ):

143122 Radius of an air bubble at the bottom of the lake is $r$ and it becomes $2 r$ when the air bubble rises to the top surface of the lake. If $P \mathrm{~cm}$ of water be the atmospheric pressure, then the depth of the lake is:

143118 A boy can reduce the pressure in his lungs to $750 \mathrm{~mm}$ of mercury. Using a straw he can drink water from a glass upto the maximum depth of (atmospheric pressure $=760 \mathrm{~mm}$ of mercury; density of mercury $=13.6 \mathrm{gcm}^{-3}$ )

143119 The area of cross-section of one limb of an $U$ tube is twice that of other. Both the limbs contain mercury at the same level. Water is poured in the wider tube so that mercury level in it goes down by $1 \mathrm{~cm}$. The height of water column is (density of water $=10^{3} \mathrm{~kg} \mathrm{~m}^{-3}$, density of mercury $=13.6 \times 10^{3} \mathrm{~kg} \mathrm{~m}^{-3}$ )

143120 The height of the dam, in a hydroelectric power station is $10 \mathrm{~m}$. In order to generate $1 \mathrm{MW}$ of electric power, the mass of water (in $\mathrm{kg}$ ) that must fall per second on the blades of the turbines is

143121 What is the velocity $v$ of a metallic ball of radius $r$ falling in a tank of liquid at the instant when its acceleration is one-half that of a freely falling body? (The densities of metal and of liquid are $\rho$ and $\sigma$ respectively, and the viscosity of the liquid is $\eta$ ):

143122 Radius of an air bubble at the bottom of the lake is $r$ and it becomes $2 r$ when the air bubble rises to the top surface of the lake. If $P \mathrm{~cm}$ of water be the atmospheric pressure, then the depth of the lake is:

143118 A boy can reduce the pressure in his lungs to $750 \mathrm{~mm}$ of mercury. Using a straw he can drink water from a glass upto the maximum depth of (atmospheric pressure $=760 \mathrm{~mm}$ of mercury; density of mercury $=13.6 \mathrm{gcm}^{-3}$ )

143119 The area of cross-section of one limb of an $U$ tube is twice that of other. Both the limbs contain mercury at the same level. Water is poured in the wider tube so that mercury level in it goes down by $1 \mathrm{~cm}$. The height of water column is (density of water $=10^{3} \mathrm{~kg} \mathrm{~m}^{-3}$, density of mercury $=13.6 \times 10^{3} \mathrm{~kg} \mathrm{~m}^{-3}$ )

143120 The height of the dam, in a hydroelectric power station is $10 \mathrm{~m}$. In order to generate $1 \mathrm{MW}$ of electric power, the mass of water (in $\mathrm{kg}$ ) that must fall per second on the blades of the turbines is

143121 What is the velocity $v$ of a metallic ball of radius $r$ falling in a tank of liquid at the instant when its acceleration is one-half that of a freely falling body? (The densities of metal and of liquid are $\rho$ and $\sigma$ respectively, and the viscosity of the liquid is $\eta$ ):

143122 Radius of an air bubble at the bottom of the lake is $r$ and it becomes $2 r$ when the air bubble rises to the top surface of the lake. If $P \mathrm{~cm}$ of water be the atmospheric pressure, then the depth of the lake is:

143118 A boy can reduce the pressure in his lungs to $750 \mathrm{~mm}$ of mercury. Using a straw he can drink water from a glass upto the maximum depth of (atmospheric pressure $=760 \mathrm{~mm}$ of mercury; density of mercury $=13.6 \mathrm{gcm}^{-3}$ )

143119 The area of cross-section of one limb of an $U$ tube is twice that of other. Both the limbs contain mercury at the same level. Water is poured in the wider tube so that mercury level in it goes down by $1 \mathrm{~cm}$. The height of water column is (density of water $=10^{3} \mathrm{~kg} \mathrm{~m}^{-3}$, density of mercury $=13.6 \times 10^{3} \mathrm{~kg} \mathrm{~m}^{-3}$ )

143120 The height of the dam, in a hydroelectric power station is $10 \mathrm{~m}$. In order to generate $1 \mathrm{MW}$ of electric power, the mass of water (in $\mathrm{kg}$ ) that must fall per second on the blades of the turbines is

143121 What is the velocity $v$ of a metallic ball of radius $r$ falling in a tank of liquid at the instant when its acceleration is one-half that of a freely falling body? (The densities of metal and of liquid are $\rho$ and $\sigma$ respectively, and the viscosity of the liquid is $\eta$ ):

143122 Radius of an air bubble at the bottom of the lake is $r$ and it becomes $2 r$ when the air bubble rises to the top surface of the lake. If $P \mathrm{~cm}$ of water be the atmospheric pressure, then the depth of the lake is: