Question 4731:

Which of the following conditions will make water boil at a temperature of 100 degrees Celsius when the atmospheric pressure is \(750 \mathrm{mmHg}\) ?

A. Increase the external pressure
B. Reduce the external pressure
C. Heat more rapidly at the same pressure
D. Reduce the external pressure by a quarter

Question 4732:

A solid weighs \(4.8 \mathrm{~g}\) in air, \(2.8 \mathrm{~g}\) in water and \(3.2 \mathrm{~g}\) in kerosene. The ratio of density of the solid to that of the kerosene is ____________

A. 12
B. 3
C. 2
D. \(3 / 2\)
E. \(5 / 4\)

Question 4733:

The extension in spring when \(5 \mathrm{~g}\) weight was hung from it was \(0,56 \mathrm{~cm}\). if Hooke's law is obeyed, what is the extension caused by a load of \(20 \mathrm{~g}\) weight?

A. \(1.12 \mathrm{~cm}\)
B. \(2.14 \mathrm{~cm}\)
C. \(2.52 \mathrm{~cm}\)
D. \(2.80 \mathrm{~cm}\)
E. \(2.24 \mathrm{~cm}\)

Question 4734:

The ice and steam points of a mercury-in-glass thermometer of centigrade scale and of uniform bore correspond respectively to \(3 \mathrm{~cm}\) and 19 em lengths of the mercury thread. When the thread is \(12 \mathrm{~cm}\), the temperature is ____________

A. \(32^{\circ} \mathrm{C}\)
B. \(48^{\circ} \mathrm{C}\)
C. \(56^{\circ} \mathrm{C}\)
D. \(65^{\circ} \mathrm{C}\)
E. \(75^{\circ} \mathrm{C}\)

Question 4735:

An electric cell has an internal resistance of 2 ohms, a current of \(0.5 \mathrm{~A}\) is found to flow when \(a\) resistor of 5 ohms resistance is connected across it. What is the electromotive force of the cell?

A. 5 volts
B. \(3.5\) volts
C. \(2.5\) volts
D. 1 volt
E. 10 volts