Home
Class 12
PHYSICS
Four resistances carrying a current show...

Four resistances carrying a current shown in Fig. `7.41` are immersed in a box containing ice at `0^(@)C`. How much ice must be put in the box every `10 min` to keep the average quantity of ice in the box constant? Latent heat of ice is `80 calg^(-1)`.

Text Solution

Verified by Experts

Total resistance `R=2xx(5xx10)/(5+10)=(20)/(3)Omega`
heat produced in 5 minute `=I^(2)Rt=5xx5xx(20)/(3)xx5xx 60=50000J`
Latent heat `L=80xx4.2xx10^(3)J//kg`, mass of ice melted , `m=(H)/(L)=(50000)/(80xx4.2xx10^(3))=0.1488` kg=148.8g.
Promotional Banner

Similar Questions

Explore conceptually related problems

When 1 kg of ice at 0^@ C melts to water at 0^@ C, the resulting change in its entropy, taking latent heat of ice to be 80 "cal/".^@C is ____

A stone of 0.36 m^(2) cross -sectional area and 0.1 m thickness has its lower surface in contact with water at 100^(@)C and upper surface in contact with ice at 0^(@)C . If 4.8 kg ice melting in 1 hour, then what is the thermal conductivity of stone ? Latent heat of fusion of ice is 3.36xx10^(5)" J/kg" .

A refrigerator converts 100 g of water at 25^(@)C into ice at -10^(@)C in one hour and 50 minutes. The quantity of heat removed per minute is (specific heat of ice = 0.5 "cal"//g^(@)C , latent heat of fusion = 80 "cal"//g )

A refrigerator converts 100 g of water at 25^(@)C into ice at -10^(@)C in one hour and 50 minutes. The quantity of heat removed per minute is (specific heat of ice = 0.5 "cal"//g^(@)C , latent heat of fusion = 80 "cal"//g )

A metallic rod of cross-sectional area 20 cm^(2) , with the lateral surface insulated to prevent heat loss, has one end immersed in boiling water and the other in ice water mixture. The heat conducted through the rod melts the ice at the rate of 1 gm for every 84 sec. The thermal conductivity of the rod is 160 Wm^(-1)K^(-1) . Latent heat of ice=80 cal/gm, 1 ca=4.2 joule. What is the length (in m) of the rod?

If 10 g of ice at 0^(@)C is mixed with 10 g of water at 40^(@)C . The final mass of water in mixture is (Latent heat of fusion of ice = 80 cel/g, specific heat of water =1 cal/g""^(@)C )

A 'thermacole' icebox is cheap and efficient method for storing small quantities of cooked food in summer in particular. A cubical icebox of side 30 cm has a thickness of 5.0 cam if 4.0 kg of ice is put in the box, estimate the amount of ice remaining after 6 h. The outside temperature is 45^(@)C , and coefficient of thermal conductivity of thermacole is 0.01" Js"^(-1)m^(-1)K^(-1) . [Heat of fusion of water =335xx10^(3)" Jkg"^(-1) ]

A metal rod AB of length 10x has its one end A in ice at 0^@C , and the other end B in water at 100^@C . If a point P one the rod is maintained at 400^@C , then it is found that equal amounts of water and ice evaporate and melt per unit time. The latent heat of evaporation of water is 540cal//g and latent heat of melting of ice is 80cal//g . If the point P is at a distance of lambdax from the ice end A, find the value lambda . [Neglect any heat loss to the surrounding.]

A' thermacole' icebox is a cheap and an efficient method for storing small quantities of cooked food in summer in particular. A cubical icebox of side 30 cm has a thickness of 5.0 cm. "if "4.0 kg of ice is put in the box, estimate the amount of Ice remaining after 6 h. The outside temperature is 45^(@) C and co-efficient of thermal conductivity of thermacole is 0.01 J s^(-1) m^(-1) K^(-1) . [Heat of fusion of water = 335 xx 10^(3) J kg^(-1) ]

2kg of ice at 20^@C is mixed with 5kg of water at 20^@C in an insulating vessel having a negligible heat capacity. Calculate the final mass of water remaining in the container. It is given that the specific heats of water & ice are 1kcal//kg//^@C and 0.5 kcal//kg//^@C while the latent heat of fusion of ice is 80kcal//kg