Newton’s law of cooling is a special case of

1.  Wien’s displacement law

2.  Kirchoff 's law

3.  Stefan’s law

4.  Planck’s law.

            
1. a

2. b

3. c

4. d

A hot liquid is kept in a big room. The logarithm of the numerical value of the temperature difference between the liquid and the room is plotted against time. The plot will be very nearly

1.   a straight line

2.   a circular arc

3.   a parabola

4.   an ellipse.

A body cools down from \(65^\circ \text{C}\) to \(60^\circ \text{C}\) in \(5\) minutes. It will cool down from \(60^\circ \text{C}\) to \(55^\circ \text{C}\) in: