2 Thermos flask reduces heat loss by: A Conduction only B Convection only C Radiation only D All three modes
6 In solids, particles are: A Far apart and free B Closely packed and vibrate about fixed positions C Completely free to move D Not moving at all
9 Critical temperature is the temperature at which: A Resistance increases B Material melts C Material becomes superconducting D Gas liquefies
10 Which of the following expands the most on heating? A Solids B Liquids C Gases D All expand equally
11 Gas pressure is due to: A Weight of gas B Collisions of gas particles C Volume of gas D Temperature only
12 Pressure of gas decreases if: A Temperature increases B Volume decreases C Volume increases D Collisions increase
14 Which activity increases greenhouse gases? A Plantation B Recycling C Burning fossil fuels D Rainfall
15 High specific heat capacity of water helps in: A Rapid heating B Climate moderation C Fast cooling D Heat insulation
16 Superconductors are mainly used in: A Electric heaters B Transformers C MRI machines D Electric bulbs
17 Which type of wave requires a material medium? A Electromagnetic wave B Mechanical wave C Light wave D Radio wave
19 Evaporation takes place at: A Boiling point only B Melting point C All temperatures D Freezing point
20 As a tsunami reaches shallow water, its height: A Decreases B Remains same C Increases D Becomes zero