CBSE Science Set- 2 Guess Paper 2013, given here.
1. Arrange the following metals. In a decreasing order of activity :
Na, K, Cu, Ag Na, K, Cu, Ag
2. Draw the electron- dot structure of ethane molecule.
3. What kind of mirrors is used in big shopping stores to watch activities of customers?
4. The pH values of three solutions A, B and C having equal molar concentration are respectively 2.0, 7.0 and 13.0 at 298 K. Which of the three solutions represents an acid solution?
5. An electron beam is moving horizontally from south to north in the vertical component of earth‟s magnetic field directed downward. In which directions will the beam deflected? State the rule also.
6. a-what is meant by power of accommodation of eye? b-how does focal length of the eye lens change when we shift looking from adistant object to a nearby object?
7. Why are coal and petroleum called fossil fuels? Name the two elements which are present both in CNG and petroleum?
8. State the position of hydrocarbon in modern periodic table? Where are isotopes of the same elements having different atomic masses placed in the periodic table?
9. An electric heater is used on 220 V supply and takes a current of 3.4 A. Calculate (i) its power and (ii) its resistance, when it is in use.
10. What is a redox reaction? When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?