Science 2 Marks Questions

Why do we prefer light coloured clothes in summer and dark coloured clothes in winter?

At a camp site, there are tents of two shades. One made with black fabric and the other with white fabric. Which one will you prefer for resting on a hot summer afternoon? Give reason for your choice.
Would you like to prefer the same tent during winter?

Observe the given figure, water is being boiled in a pan of wide base.

(i) Which position Por T will feel warmer?
(ii) Fill up the boxes Pand T to indicate the mode of flow of heat to the hand.

For setting curd, a small amount of curd is added to warm milk. The microbes present in the curd help in setting if the temperature of the mixture remains approximately between 35°C to 40°C. At places where room temperature remains much below the range, setting of curd becomes difficult. Suggest a way to set curd in such a situation.

A laboratory thermometer A is kept 7 cm away on the side of the flame while a similar thermometer B is kept 7 cm above the flame of a candle as shown in figure. Which of the thermometers A or B will show a greater rise in temperature? Give reason for your answer.

In the arrangements A and B as shown in figure, pins Pand Q are fixed to a metal loop and an iron rod with the help of wax. In which case, both the pins are likely to fall at different times? Explain.

A circular metal loop is heated at point O as shown in figure.

(i) In which direction, would heat flow in the loop?
(ii) In which order, the pins at points P, Qand R fixed with the help of wax fall if points O, P, Q and R are equidistant from each other?

Last Sunday, Pooja on her week off entered in her kitchen to cook rice for her family in lunch time. The moment she put fry pan on the gas stove and lighted it through the matchstick, all of sudden her 5 years small daughter entered into the kitchen and tends to touch the hot fry pan. At the same time, Pooja saw her and pushed her away from the hot fry pan. In this way, she saved her child.
(i) Explain why are the fry pan provided with the plastic handles?
(ii) Mention the values represented by Pooja here towards her 5 years small daughter.

Explain the reason for the shiny reflectors of room heaters.

Briefly explain, why do the kites and eagles fly without flapping their wings?

The freezer is located at the top of the refrigerator. Explain why?

The handle of a pressure cooker is covered with the thick plastic. Explain why?

Briefly explain the maximum and minimum thermometers.

Instead of water explain the reason, why is the mercury used in the thermometer?

State the limitation of clinical thermometer.

The clinical thermometer is not used to measure high temperature. Why?

Describe the effects of heat.

You may have noticed that a few sharp jerks are given to clinical thermometer before using it. Why is it done so?

In places of hot climate, it is advised that the outer walls of houses be painted white. Explain.

Look at the figure, mark where the heat is being transferred by conduction, by convection and by radiation.

Discuss why wearing more layers of clothing during winter keeps us warmer than wearing just one thick piece of clothing.

State similarities and differences between the laboratory thermometer and the clinical thermometer.

The method of transfer of heat, i.e. convection is only possible in fluids. Explain why?

Write differences between clinical thermometer and laboratory thermometer.