Download SCIENCE -X - Kendriya Vidyalaya Misa Cantt

HOME WORK FOR SUMMER BREAK
SUBJECT- Science
class- X
Part-A
Q. 1 While eating you are advised not to talk. Why are you advised so?
Q. 2 We say that movement is a characteristic of living organisms but we always
don’t see visible movements in plants. Comment.
Q. 3 If a person is working on a treadmill in a gymnasium, will it effect his rate of
breathing? How?
Q. 4 If you compare your rate of breathing by feeling your chest movement with
the number of times a fish opens and closes its mouth. Which willbe higher and
why?
Q. 5 Mucus is not used for churning the food or digesting it. Then why is it
secreted in the stomach?
Q. 6 In the process of Photosynthesis food A is preparedwhich gets converted into
food B. What are A and B? Why is A converted to B?
Q. 7 When we are asleep we are not performing any activity still our life processes
are going on. Why?
Q. 8 Leaves of a healthy potted plant were coated with petroleum jelly. How will it
affect the plant? State two reasons.
Q9. a) Draw the diagram of heart and label its four chambers.
b) Construct a table to show the functions of thesefour chambers.
Define the following:
(a)Saprotrophs
(b)Parasites
(c)Photosynthesis
(d)Transpiration
10. How are flats digested in our bodies? Where does this process take place?
11.Draw a neat & labelled diagram of the human Excretory System.
(ii)Name the procedure used in working of artificial kidneys.
(iii)How is urine produced in human body?
12.What is the role of acid produced in the stomach?
13.Glucose Oxidize to provide energy in various organisms. (Depict by flow chart
only)
Holiday Homework, 2015-16
Kendriya Vidyalaya Misacantt, Nagaon
Class: X
Sub: Science (physics)
Students should take extra answer sheet/copy. Don’t use your school copy.
A. Electric current and circuit
Q1. What does an electric circuit mean?
Q2. Define the unit of current.
Q3. Calculate the number of electrons constituting one coulomb of charge.
B. Elect6ric potential and potential difference
Q1. Name a device that helps to maintain a potential difference across a conductor.
Q2. What is meant by saying that the potential difference between two points is 1 V?
Q3. How much energy is given to each coulomb of charge passing through a 6 V battery.
C. Factors on which resistance of a conductor depends.
Q1. On what factors does the resistance of a conductor depend?
Q2. Will current flow more easily through a thick wire or a thin wire of the same material, when
connected to the same material? Why?
Q3. Let the resistance of an electrical component remains constant while the potential across
the two ends of the component decreases to half of its former value. What change will occur in
the current through it?
Q4. Why are the coils of electric toasters and electric irons made of an alloy rather than a pure
metal?
D. Combination of resistors
Q1.Draw the schematic diagram of a circuit consisting of a battery of three cells of 2 V each, a 5
ohm resistor, an 8 ohm resistor and a 12 ohm resistor and a plug key, all connected in series.
Q2. Redraw the above circuit putting in an ammeter to measure the current through the
resistors and a voltmeter to measure the potential difference across the 12 ohm resistor. What
would be the readings in the ammeter and the voltmeter/
Q3. Judge the equivalent resistance when the following are connected in parallel
(a) 1 ohm and 106
(b) 1 ohm and 103 ohm and 106 ohm
Q4. An electric lamp of 100 ohm, a toaster of resistance 50 ohm and a water filter of resistance
500 ohm are connected in parallel to a 220 V source. What is resistance of an electric iron
connected to the same source that takes as much current as all three appliances, and what is
the current through it?
Q5. What are the advantages of connecting electrical devices in parallel with the battery instead
of connecting them in series?
Q6. How can three resistors of resistances 2 Ω, 3 Ω and 6 Ω be coonected to give a total
resistance of (a) 4 Ω and (b) 1 Ω ?
Q7. What is (a) highest (b) the lowest total resistance that can be secured by combinations of
four coils of resistance 4 Ω, 8 Ω, 12 Ω 24 Ω ?
E. Heating effect of current
Q1. Why does the cord of an electric heater not glow while the heating element does?
Q2. Compute the heat generated while transferring 96000 C of charge in one hour through a
potential difference of 50 V.
Q3. An electric iron of resistance 20 Ω takes a current of 5 A. calculate the heat developed in 30s
F. Electric power
Q1. What determines the rate at which energy is delivered by a current ?
Q2. An electric motor takes 5A from a 220 V line. Determine the power of the motor and energy
consumed in 2 h.
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