Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main202312 Apr 2023Morning ShiftPhysicsThermal Properties of MatterActual

A body cools from 80 o C to 60 o in 5 minutes. The temperature for the surrounding is 20 o C . The time it takes to cool from 60 o C to 40 o C is

Options

  1. A450   s
  2. B420   s
  3. C500   s
  4. D25 3   s

Correct answer

C. 500   s

Step-by-step solution

The formula to calculate the rate of cooling of the object is given by d T d t = K T f + T i 2 - T 0       . . . 1 For the first case, it can be written, using equation (1) that 80 - 60 5 = K 80 + 60 2 - 20 4 = 50 K       . . . 2 If t is the required time for the second case, from equation (1), it can be written that 60 - 40 t = K 60 + 40 2 - 20 20 t = 30 K       . . . 3 Divide equation (2) by equation (3) and solve to calculate the required time. 4 20 t = 50 K 30 K &#86

Practice Thermal Properties of Matter on Quantrex Academy →

More from Thermal Properties of Matter

As shown in the figure, an insulated container is fitted with a thermally conducting but immovable partition (P₁) and a freely movable but thermally insulated piston (P₂) . The par 2026The heat extracted out of x gram of water initially at 50°C to cool it down to 0°C is sufficient to evaporate (1000 - x) gram of water also initially at 50°C . The value of x (clos 2026The temperature of a metal strip having coefficient of linear expansion is increased from T₁ to T₂ resulting in increase of its length by L₁ . The temperature is further increased 2026Which of the following best represents the temperature versus heat supplied graph for water, in the range of -20^ C to 120^ C ? 202610 kg of ice at -10^ C is added to 100 kg of water to lower its temperature from 25 ^ C . Consider no heat exchange to surroundings. The decrement to the temperature of water is _ 2026A brass wire of length 2 m and radius 1 mm at 27^ C is held taut between two rigid supports. Initially it was cooled to a temperature of -43^ C creating a tension T in the wire. Th 2026Rods x and y of equal dimensions but of different materials are joined as shown in figure. Temperatures of end points A and F are maintained at 100^ C and 40^ C respectively. Given 2026An aluminium and steel rods having same lengths and cross-sections are joined to make total length of 120 cm at 30^ C . The coefficient of linear expansion of aluminium and steel a 2026 Full Thermal Properties of Matter list All JEE Main PYQs