A metal ball of radius 0.1 m at a uniform temperature of 90°C is left in air at 30°C. The density and the specific heat of the metal are 3000 kg/m3 and 0.4 kJ/kg.K respectively. The heat transfer co-efficient is 50 W/m2.K Neglecting the temperature gradients inside the ball, the time taken (in hours) for the ball to cool to 60°C is_________________?

Chemical Engineering Mcqs

A metal ball of radius 0.1 m at a uniform temperature of 90°C is left in air at 30°C. The density and the specific heat of the metal are 3000 kg/m3 and 0.4 kJ/kg.K respectively. The heat transfer co-efficient is 50 W/m2.K Neglecting the temperature gradients inside the ball, the time taken (in hours) for the ball to cool to 60°C is_________________?

(A)  555

(B)  55.5

(C)  0.55

(D)  0.15

Submitted By :Ali Uppal

---

Share this...

Facebook

Twitter

Linkedin

Whatsapp

---

IF YOU THINK THAT ABOVE POSTED MCQ IS WRONG.

PLEASE COMMENT BELOW WITH CORRECT ANSWER AND ITS DETAIL EXPLANATION.

---

Related Mcqs

• Previous:The ratio of momentum diffusivity to thermal diffusivity is the ______________ number?
• Next:Heat transfer occurs by natural convection because change in temperature causes difference in__________________?

---

Leave a Reply

Your email address will not be published. Required fields are marked *