HOLIDAY HOMEWORK
CLASS X
SCIENCE
Session 2017-18
1. a) Classify the following reactions into different types:
i)
(s)
(s) +
ii) CH4 (g) + 2O2 (g)
(g) +
(g)
CO2 (g) + 2H2O (g)
iii) AgNO3 (aq) + NaCl (aq)
AgCl (s) + NaNO3 (aq)
2. Identify the substance oxidised , the substance reduced, oxidizing agent and reducing agent in the
following reactions:
a) 2PbO + C
2Pb + CO2
b) MnO2 + 4HCl
MnCl2 + 2H2O +Cl2
c) H2S + Cl2
2HCl + S
3. Balance the following:
a) NaOH + H2SO4
b) H2S + SO2
c) Fe + H2O
Na2SO4 + H2O
S + H2O
Fe3O4 + H2
4.
5. A wire of resistivity ρ is stretched to double its length. How does it affect the (a) resistance
(b) resistivity?
6. A wire of resistance 10 ohm is bent in the form of a closed circle. What is the effective
resistance between the two points at the end of any diameter of the circle?
7. (a) How does the resistance of a wire change when
(i) its length is tripled ?
(ii) its radius is tripled ?
(iii) its material is changed to one whose resistivity is three times ?
(b) List two reasons why nichrome is used for making heating element
of electrical appliances.
8. Which has more resistance: 100W bulb or 60W bulb?
9. Ammeter burns out when connected in parallel. Give reasons.
10.Two fuse wire A and B of the same length are rated 15A and 5A. Which amongst the A and B
will be thicker and why?