Cool off time is given to read and understand the questions
The score of each question is given along with it
If there is an OR between any two questions, you may answer only one
among them
1) Among the following which is voltage at which electricity is generated at the
power station
a) 230V b) 220kV c) 11 kV d) 110 kV 1
2) The current in the primary coil of a transformer is 2A and that in the
secondary is 3.5A. Which type of transformer is this ? 1
3) Fill in the blanks identifying the correct relation
Temperature: K , Latent heat of fusion : ………………. 1
4) Arrange the following in the increasing order of their frequency
Orange, Blue , Violet , Yellow, Red 1
5) The persistence of sound as a result of multiple reflection is called —— 1
6) Pick out the odd one from the following
Discharge lamps, CFL, Microwave oven , LED lamps 1
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Prepared By Kannan, Paruthipully . Maths blog Team Palakkad
7) Explain the reason why infrared rays are used to take photograph of distant
objects ? 2
8) A boy connected a bulb, a solenoid, a12V battery and a switch as shown in the
figure and observe the brightness of the bulb
When the 12V DC is replaced by 12V AC source the brightness of the bulb
decreased this is due to …………………………….
If a soft iron core is inserted on the solenoid what happens to the
brightness in of the bulb in case of 12V c AC. Explain 2
9)
State the condition in which a vibrating body is said to be in resonance
with other body
Write an experiment to illustrate the resonance of sound 2
10) It is marked as 20W, 240V on a CFL
What is the energy consumed in Joule by the CFL if it works for one second
How many hours it has to work to utilize one unit (1kWh) of electrical
energy 2
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Prepared By Kannan, Paruthipully . Maths blog Team Palakkad
11) Which of the following has higher resistance ?
a) 1500W, 240V motor
b) 100W, 240V bulb ? Give proper reason for your answer 2
12) On a day the increase in atmospheric temperature is found to be 70
C. What is
the corresponding increase in temperature in
Fahrenheit Scale
Kelvin scale
Give proper reason for your answer
OR
In the above figure temperature against -400
C in Fahrenheit scale is
indicated by a rectangle Find the corresponding temperature in
Fahrenheit scale. What is the corresponding temperature in Kelvin
scale 3
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Prepared By Kannan, Paruthipully . Maths blog Team Palakkad
13)
In the above picture the path of light coming from the search light is clearly
visible.
Name the phenomena
Explain the phenomena and write why the path of light is clearly
visible 3
14) In a house 5 CF lamps each of 20W, works for 5 hours, 2 fans each of 60W,
works for 6 hours, a TV of 100W works for 2 hours and a motor of power IHP
works for 10 minutes daily.
What is the energy consumption shown by watt hour meter per day
I f the average rate for I unit of electricity is 3 rupees . What is the cost
electricity for two months ? ( Take IHP = 750W) 3
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Prepared By Kannan, Paruthipully . Maths blog Team Palakkad
15) Evaporation is the process by which molecules escape from the surface of a
liquid and as a result the liquid gradually changes itself into gaseous state
a) Identify from the following, the appropriate statement regarding
evaporation
Requires external energy
Takes place at fixed temperature
Takes place quickly
Causes cooling
b) Write any three factors that influence evaporation and write how these
factors affects evaporation
c) Doctors suggest to keep wet clothes on the forehead of a person suffering
from severe fever. What is the advantage of this ? 3
16) A boy draws the plan of a simple household electric circuit diagram as shown
in the figure. He proposes to connect a bulb and a fan in the plan. But after
drawing upto the main switch he does not know where and how to include it
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Prepared By Kannan, Paruthipully . Maths blog Team Palakkad
Suggest the location of the main fuse
Copy the diagram in your answer sheet and mark the main fuse and also
draw the connections of fan and bulb including ELCB and MCB 4
17) A hot liquid at 900
C is taken in a test tube and it is allowed to cool. The
results obtained are given in the graph. Analyse the graph carefully and answer
the following questions
Find out freezing point of the liquid.
Why is the portion BC horizontal
What is the state of substance represented by CD
What is the laboratory temperature
OR
What is the heat required to convert 100gm ice at 00
C to steam at 100O
C
( Specific heat capacity of water = 4200 J/KgK , Latent heat of fusion of ice =
335 x 103
J/Kg, Latent heat of vaporization of water = 226 x 104