Punakha Higher Secondary School
Trial Examination, 2014
Subject: Physics
Writing Time: 1
Class: X
Total Marks: 80
1
Hours
2
SECTION A (40 marks)
Compulsory: To be attempted by all candidate
Question 1
[15]
A) Directions: Each questions in this part is followed by four possible choices of answers. Choose
the correct answer and write it in the answer sheet.
i)
ii)
iii)
When the MCB of the house circuit is switched off, it disconnects the
a) live wire b) earth wire c) neutral wire d) live and neutral wire
A fuse wire must have
a) Low resistance and high melting point
b) high resistance and low melting point
b) low melting point and low resistance
d) high resistance and high melting point
If a length of a given wire is doubled by stretching it, its resistance will increase by
a)
iv)
v)
1
times
4
b)
1
times
2
c) 2 times d) 4 times
Which of the following combination of statements given below best describes a noise?
I)
Sudden changes of loudness or intensity
II)
No sudden changes of loudness or intensity
III)
Frequency is generally low
IV)
Frequency is generally high.
a) I and II b) I and III c) II and IV d) III and IV
The diagram below shows two incident rays A and B which merge out. The device used in
the box marked ‘X’ is a
a) Prism b) convex lens
c) concave lens
d) concave mirror
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vi)
vii)
viii)
When an object is placed at a distance 2 f from a convex lens of focal length f , the image
formed will be
a) Same size b) at infinity c) magnified d) diminished
The total internal reflection occurs when the angle of incidence is
a) Equal to the critical angle
b) less than the critical angle
b) c) greater than the critical angle
d) equal to the angle of refraction
Read the following statements.
I)
Wires are corrosive
II)
Wires are non- corrosive
II)
Wires have low resistance
iv)
Wires have high resistance
Which combination of the statements given above is the characteristics of a high tension
wire?
ix)
x)
xi)
xii)
xiii)
xiv)
xv)
a) I and III b) I and IV c) II and III d) II and IV
When a tuning fork is struck against a rubber pad, it executes
a) Resonance b) Free Vibration c) Forced Vibration d) Damped Vibration
The equivalent resistance between points A and B in the diagram given below is
a) 9
b) 6
c) 5
d) 3
One joule of work is said to be done when a force of
a) 1 N displaces a body by 1 m
b) 1 N displaces a body by 1 cm
b) 1 dyne displaces a body by 1 m
d) 1 dyne displaces a body by 1 cm
The density of water at 4⁰C is
a) 100 kgm3 b) 100 gcm 3 c) 1 kgm3 d) 1 gcm 3
All the statements given below are true EXCEPT
a) If the atmospheric pressure falls suddenly, it indicates the arrival of storm
b) If the atmospheric pressure falls gradually, it indicates fair weather.
c) At higher altitudes, nose bleeding may occur due to reduced air pressure.
d) At lower altitudes, ears gets blocked due to increased air pressure
The potential difference required to pass a current of 0.2 A in a wire of resistance 20 is
a) 3 V b) 4 V c) 6 V d) 10 V
If a body weighs 600 N on earth, its weight on the moon will be
a) 60 N b) 100 N c) 600 N d) 6000 N
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B) Match each item under column A with the most appropriate item in column B. Rewrite the
correct matching pairs in your answer sheet.
[5]
Column A
Column B
1. Aperture
a) volts
2. 15,000 Hz
b) joule
3. Resistance
c) ampere
4. Unit of energy
d) watt
5. Potential difference
e) ultrasonic range
f) f-number
g) audible range
h) newton
i) ohm
j) shutter
C) Fills in the blanks by writing suitable word/s.
a) A photographic camera is used to record a …………………. Image.
b) The work done by a body moving in a complete circular path is………………….
c) A barometer is used to measure ………………………………..
d) In a third class lever, the mechanical advantage is ………….. than unity.
e) The rate of flow is charge is …………………….
[5]
D) Rewrite the following statements by replacing the words in BOLD only.
a) In household circuitry, the appliances are connected in series.
[5]
b) If the refractive index of glass with respect to air is
2
, then the refractive index of air with
3
respect to glass is 0.66.
c) The sound that produces a pleasant effect on our ear is called noise.
d) The current flowing through a metallic conductor at a constant temperature is proportional
to the resistance applied to its end.
e) One horse power is equal to 476 W.
E) Answer the following questions.
i)
An electric bulb is marked 250 W, 230 V. How much energy does it consume in
1. 10 hours?
[1]
2. 150 minutes?
[1]
ii)
Why will body weigh less in air than in a vacuum?
[1]
iii)
How does the resistance of a wire depend on its thickness? Give reason to support your
answer.
[2]
iv)
Write one difference between a simple barometer and an aneroid barometer.
[1]
v)
How is it possible to recognize a person by hearing his voice without seeing him?
[1]
vi)
Write down two differences between real image and virtual image.
[2]
vii)
How is force related to momentum of the body?
[1]
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Section B (40 marks)
Attempt any four questions.
Question 2
a) i) state the S.I units of
1. Electrical power
[1]
2.
Electrical energy
ii) What is the present internal colour coding of
[1]
1. Live wire?
2. Neutral wire
b) i) What is 1 Ohm? Write the mathematical expression for resistance.
[2]
2
ii) Find the work done in lifting a box of mass 5 kg to a height of 8m. ( Take g=10m/s ) [2]
c) i) How does the density of a body determines whether it will float or sink in water?
[1]
ii) State Pascal’s law.
[1]
iii) The density of mercury is 13.6 x 10 3 kgm3 . Calculate its relative density.
[2]
Question 3
a) i) What is meant by resonance?
ii) State the condition under which resonance occurs.
iii) Give four examples of phenomena based on resonance.
iv) Give two conditions when the work done is zero.
b) The diagram below is to be used with questions that follow.
i)
ii)
iii)
iv)
Calculate the total resistance connected in parallel.
Calculate the total resistance of the circuit.
What is the reading of the ammeter?
Calculate the voltage across 2 resistor.
[1]
[1]
[2]
[1]
[1]
[1]
[2]
[1]
Question 4
a) i) What force is required to accelerate a 200 kg car from 5ms 1 to 25ms 1 in 5s?
[2]
ii) Santosh stands 200 m away from a high wall and blows a whistle. He hears the echo after
1.2s. Calculate the velocity of the sound.
[2]
iii) Tashi uses yellow and blue paint to obtain green paint. Why?
[1]
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b) The following figure shows an arrangement of a single moving pulley. Study the diagram
carefully and answer the questions that follow:
1. Calculate the mechanical advantage of the system.
[1]
2. Calculate the load that can be lifted by an effort of 25 N.
[1]
c) Mr. Sonam uses five 60 W electrical bulbs and four 40 W fluorescent tubes in his house for 8
hours. Calculate the cost of electricity used, if electric energy cost is Nu. 2 per KWh.
[3]
Question 5
a) i) Name the part which is used to regulate the light in the:
1. human eye
2. Camera
[1]
ii) When an object is placed at 10cm, the magnification produced by a convex lens is 4. Find the
distance of the object.
[2]
b) i) What is a switch?
ii) Why is the earth pin longer and thicker than the rest of the pins?
c) i) Explain the application of Pascal’s Law in a hydraulic press.
ii) A sound made in front of a tall building is heard again. Name and briefly explain the
phenomenon.
[1]
[2]
[2]
[2]
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Question 6
a) Copy the following diagram and mark on it:
1. the direction of the flow of current.
[1]
2. Magnetic polarity at ends A and B.
[1]
3. Suggest three ways of increasing strength of the magnetic field of a solenoid.
[3]
b) i) State Archimedes’ principle.
[1]
ii) Why does a red flower appear black when it is viewed in green light?
[2]
c) i) What do you mean by the term earthing?
[1]
ii) Why does the Newton’s colour disc painted with VIBGYOR appear greyish or dull white when
rotated rapidly?
[1]
Question 7
a) i) Distinguish between convex and concave lens on the basis of formation of image, when the
object is in between the optical centre and the focal point.
[1]
ii) An inclined plane is 3 m high and the length of the plane is 15m. Assuming there is no friction,
calculate the effort required to lift a load of 1000 N along the plane.
[2]
b) i) Penjor wants to take a picture of her house in the evening. What adjustments should be made
with regard to the:
1. shutter speed?
[1]
2. size of aperture?
[1]
ii) Construct a ray diagram to show the formation of an image when the object is placed at the
focus of a convex lens.
[2]
c) i) How can we find the direction of magnetic field using the right hand thumb rule?
d) Arrange the electromagnetic waves in their decreasing order of wavelength.
[1]
[2]
***************Best of Luck***************
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