Home
Class 11
PHYSICS
A body takes 5 minutes to cool from 90^(...

A body takes 5 minutes to cool from `90^(@)C` to `60^(@)C` . If the temperature of the surroundings is `20^(@)C` , the time taken by it to cool from `60^(@)C` to `30^(@)C` will be.

A

5 min

B

8 min

C

11 min

D

12 min

Text Solution

Verified by Experts

The correct Answer is:
C
Since, `(T_1-T_2)/(t)=K[(T_1+T_2)/(2)-T_0]`
`(90-60)/(5)=K((90+60)/(2)-20) ...(i)
and `(60 -30)/(t) = K ((60+30)/(2)-20)` … (ii)
By (i) and (ii) -
`t/5 = (55)/(25) implies` t= 11 minutes.
Promotional Banner

Topper's Solved these Questions

  • TRANSMISSION OF HEAT

    ERRORLESS|Exercise PAST YEARS QUESTIONS|21 Videos

  • TRANSMISSION OF HEAT

    ERRORLESS|Exercise Assertion & Reason|22 Videos

  • TRANSMISSION OF HEAT

    ERRORLESS|Exercise NCERT BASED QUESTIONS (Radiation (Stefan.s law))|25 Videos

  • THERMOMETRY, THERMAL EXPANSION AND CALORIMETRY

    ERRORLESS|Exercise ASSERTION & REASON|10 Videos

  • UNITS, DIMENSIONS AND MEASUREMENT

    ERRORLESS|Exercise ASSERTION & REASON |17 Videos

Similar Questions

Explore conceptually related problems

A body takes 4 min. to cool from 61^(@)C to 59^(@)C . If the temperature of the surroundings is 30^(@)C , the time taken by the body to cool from 51^(@)C to 49^(@)C is :

A body takes 10min to cool from 60^(@)C " to" 50^(@0C . If the temperature of surrounding is 25^(@)C , then temperature of body after next 10 min will be

A body cools from 50^(@)C to 49.9^(@)C in 5 s. the temperature of the surroundings is 30^(@)C . How long will the body, take to cool from 40^(@)C to 39.9^(@)C ?

A body takes, 4 minutes to cool from 100^(@)C to 70^(@)C , if the room temperature is 25^(@)C , then the time taken to cool from 70^(@)C to 40^(@)C will be

A metal sphere cools from 72^(@)C to 60^(@)C in 10 minutes. If the surroundings temperature is 36^(@)C , then the time taken by it to cool from 60^(@)C to 52^(@)C is

A body takes 10 min to cool from 60^(@)C " to " 50^(@)C . Temperature of surrounding is 25^(@)C . Find the temperature of body after next 10 min.

A body takes T minutes to cool from 62^@C to 61^@C when the surrounding temperature is 30^@C . The time taken by the body to cool from 46^@C to 45^@C is