JAMB - Physics (2023)
- 2Which of the following statements regarding the application of electrical conduction via gases is/are correct?
Electrical conduction in gas is applied in:
(i) The identification of gases
(ii) Lighting/fluorescent tubes
(iii) Photocells
(iv) Cathode ray oscilloscope/T.V. tubes
Trả lời(B)(i), (ii) and (iv) only - 13The surface temperature of a swimming pool on a warm day is 25ºC and the temperature at the bottom is 15ºC. If the swimming pool has a surface area of 620 \(m^2\) and a depth of 1.5m. Find the rate at which energy is transferred by conduction from the surface to the bottom of the swimming pool.
[Thermal conductivity of water (k) = 0.6071 Wm-1K-1]Trả lời(A)2.5kw - 21
What is the amount of heat required to raise the temperature of a 0.02 kg of ice cube from \(-10^oC\) to \(10^oC\) ?
[specific latent heat of fusion of ice = 3.34 x \(10^5\) \(Jkg^-1\), Specific heat capacity of water = 4200 \(Jkg^-1\) \(k^-1\)Specific heat capacity of ice = 2100 \(Jkg^-1\) \(k^-1\)
Trả lời(D)7940 J - 32

A block of mass 0.5 kg is suspended at the 40 cm mark of a light metre rule AB that is pivoted at point E, the 90 cm mark, and is kept at equilibrium by a string attached at point D, the 60 cm mark, as shown in the figure above. Find the tension T in the string.
[Take g = \(10 ms-2\) ]Trả lời(A)16.67N - 39An open-tube mercury manometer is used to measure the pressure in a gas tank. When the atmospheric pressure is 101,325 \(P_a\), what is the absolute pressure in \(P_a\) in the tank if the height of the mercury in the open tube is 25 cm higher. density of mercury = \(13600kg/m^3, g = 9.8m/s^2\)Trả lời(D)134,645 Pa










