Why are burns caused by the steam more severe than those caused by boiling water at the same temperature?
i) What is meant by specific heat capacity of a substance?
ii) Why does the heat supplied to a substance during its change of state not cause any rise in its temperature.
What will an alpha particle change into when it absorbs:
i) One electron;
ii) Two electrons?
Name the three main parts of a hot cathode ray tube. Mention one important function of each of the three main parts.
A block and tackle pulley system has a velocity ratio 3.
i) Draw a labelled diagram of this system. In your diagram, indicate clearly the points of application and the direction of the load and effort.
ii) Why should the lower block of this pulley system be of negligible weight.
i) With the help of a well-labelled diagram, show that the apparent depth of an object, such as a coin, in water is less than its real depth.
ii) How is the refractive index of water related to the real depth and the apparent depth of a column of water?
A cell of e.m.f. 1.5 V and internal resistance 1.0 ohm is connected to two resistors of 4 ohm and 2 ohm in series as shown in the figure.
Calculate the:
i) current in the circuit
ii) potential difference across the 4 ohm resistor.
iii) voltage drop when the current is flowing.
iv) potential difference across the cell.A substance is in the form of a solid at 0o C. The amount of heat added to this substance and the temperature of the substance are plotted on the following graph:
If the specific heat capacity of the solid substance os 500 J/kgo C, find from the graph:
i) the mass of the substance
ii) the specific latent heat of fusion of the substance in liquid state.i) What happens to the atomic number of an element when it emits:
1. an alpha particle;
2. a beta particle.
ii) Explain why alpha and beta particles are deflected in an electric or a magnetic field but gamma rays are not deflected in such a field.i) 1. Atomic number of an element decreases by 2, when an alpha particle is emitted out.
2. Atomic number of the element increases by 1, when a beta particle is emitted out.
ii) Alpha particles and beta particles are deflected in electric field because alpha particles are positively charged and beta particles are negatively charged. But, gamma rays are not deflected because it is uncharged.