Physics – Important Questions Bank for Kerala Board HSE 2016 Examination

1. A converging lens of shorter focal length behaves as a simple microscope.

(a) if he plots a graph between the length and period of oscillation, what will be the shape of the graph?

(B) how would you determine the value of acceleration due to gravity using l – T² graph?

( c ) explain seconds pendulum and describe how will you find the length of a seconds pendulum and that of a pendulum of period

2. Transistor can be used as an amplifier and oscillator.

(a) for a CE-transistor amplifier, the audio signal voltage across the collector resistance of 2 KΩ is 2 V. if the current amplification factor of the transistor is 100, find the input signal voltage. The base resistance is 1 KΩ.

(b) with the help of a circuit diagram, explain the working of a tuned collector oscillator. The positive feedback in the oscillator is accomplished by inductive coupling through mutual induction

3. the acceleration due to gravity (g) on the surface of the each is 9.8 m/s²

(i) define the acceleration due to gravity (g)

(ii) derive an expression for the variation of  g at a depth ‘d’ below the surface of earth.

(iii) at what height ‘h’ will the value of ‘g’ be half of that on the surface of the earth?

4. (A) the mirror equation is the relation between the object distance (u), image distance (v) and the focal length (f) of a spherical mirror.

(i) derive the mirror equation by using a ray diagram that includes a concave mirror.

(ii) A small candle, 2.5 cm in size is placed at 27 cm in front of a concave mirror of radius of curvature 36 cm. at what distance form the mirror should a screen be placed in order to obtain a clear image?

(B) A converging lens of shorter focal length behaves as a simple microscope.

(i) with the help of a schematic diagram, derive and expression for the linear magnification of a simple microscope

(ii) A simple microscope has a liner magnification of 6. When the image formed is at the near point of eye. Find the focal length of convex lens. Near point, D = 25 cm

5. (A) Thomas young demonstrated the phenomenon of interference by using the double slit experiment with two sources ‘locked in phase’.

(i) the sources ‘ locked in a phase’ are known as…..

(ii) using schematic diagram, derive an expression for the fringe width in Young’s double slit experiment

6. A mass m is suspended at one end of a spring and the other end of the spring is firmly fixed on the ceiling. If the mass is slightly depressed and released it will depressed and released it will execute oscillation.

(a) write down the expression for the frequency of oscillation of the mass.

(b) if the spring is cut into two equal halves and one half of the spring is used to suspend the same mass then obtain an expression for the ratio of periods of oscillation in two cases

( C) if this system is completely immersed in water then what happens to the oscillation?

7. the escape speed for an object from the earth is 11.2 Km/s

i) what is meant by escape speed?

ii) arrive at an expression for the escape speed form the earth

iii) explain whether the escape speed depends on the mass of the object or not

iv) the earth contains an atmosphere while the moon does not. Give the reason.

8. the magnetic flux associated with the rectangular coil of an ac generator at an instant ‘t’ is given by ɸ = NBA cos ω t.

i) Using Faradai’s law of elector-magnetic induction, arrive at an expression for the alternating emf generated in the ac generator.

ii) an ac voltage V=V_o sin ω t is applied to an inductor. Deduce the phase relation between voltage and current in the inductor

iii) if the inductor is filled with a medium of relative permeability µ_r, what happens to the phase relation between voltage and current?

9. An athlete jumps at an angle of 30^o with a maximum speed of 9.4 m/s.

i) what is the shape of the path followed by the athlete In the jump?

ii) obtain an expression to calculate the horizontal range covered by the athlete.

iii) find the range covered by him in the above jump. Suggest the angle by which the athlete can attain the maximum range.

10. A) The cyclotron is a high energy particle accelerator.

i) which one of the following particles cannot be accelerated by using a cyclotron?

i) Proton ii) Neutron iii) Alpha particle iv) singly ionized helium atom

(b) using a suitable schematic diagram arrive at an expression of the cyclotron arrive at an expression for the cyclotron frequency

11. the earth is moving around the sun in a elliptical orbit and this bring out the seasons.

i) name the physical quantity conserved in this

ii) as the earth approaches near the sun in its path, it moves faster. State whether this statement is correct or wrong. Why?

iii) Determine the duration of the day on earth if it suddenly shrinks to 1/4^th of its present size while the mass of the earth remains unchanged. (assume earth is a perfect sphere)

12. Air is blown in between tow pith ball suspended freely.

(a) what will happen to the balls?

i) they repel each other

ii) they attract each other

iii) they start oscillating

iv) they remain in their initial position

v) they fall on the ground.

(b) Give your explanation

C) derive an expression for the principle involved in this situation.

13. To investigate the inner structure of an atom, Rutherford proposed a series of experiments

i) what was the name of the experiment that lead to Rutherford’s nuclear model of atom?

ii) give an two major observations in the above experiment

“when light travels obliquely form rarer to denser medium, the refracted ray bends…the normal (away from/towards)”

(B) A tank is filled with water to a height of 12.5 cm. The apparent depth of a needle lying at the bottom of the tank is measured by a microscope to be 9.4 cm. what is the refractive index of water? If water is replaced by a liquid of refractive index 1.63 upto the same height, by what distance would the microscope have to be moved to focus on the needle again?

14. An external force is always required to break the inertia of a body which is either in the state of rest or state of rest or state of uniform motion.

i) which law governs this statement?

ii) can all forces produce acceleration? Why?

iii) A boy holding a spring balance in his hand suspend a mass 2 Kg from it. If the balance slips from his hand and falls down, find the reading of the balance while it is in the air.

15. According to Newton’s law of motion the force depends on the rate of change of momentum

i) Name the law that helps to measure force

ii) Using the above law, deduce an expression for force.

iii) A man jumping out of a moving bus falls with his head forward. What should he do in order to land safely?

16. The outer side of a circular track of radius 200 m is raised to make an angle of 15^o with the horizontal.

a) which force provides the necessary centripetal force for a car taking the circular track?

b) name the process by which the outer side of a curved track is raised a little above the inner side.

c) using the data provided in this permissible speed to avoid skidding. (Give µ s = 0.25).

17. (A) Pick the odd one out from the following ( Amplitude modulation, Frequency modulation, Pulse width modulation, Phase modulation)

(B) Drawn the block diagram of a modulator for obtaining an AM signal

18. Draw the forward and reverse biased characteristic of a pn junction semiconductor diode

(b) how does a zener diode work as a voltage regulator?

19. A balloon is ascending at the rate of 14 ms^-1 and at a height of 98 m above the ground. A stone I dropped form it

a) state whether the motion of the balloon is accelerated or retarded

b) after how much time does the stone reach the ground?

c) determine the velocity with which the stone strikes the grounds

20 . Hooke’s law states that stress α strain

a) what is the necessary condition for the above law to be valid?

b) Explain with the help of a graph, the relation between stress and strain for a given solid material under increasing tensile stress.

21. A string is stretched between two fixed supports and a note of sound is heard when it is plucked at its middle point.

i) state whether sound is propagated as longitudinal wave or transverse waves

ii) derive an expression for the frequency of sound produced in the fundamental mode of vibration

iii) what are overtones?

b) if a tuning fork is held above a resonance column, then maximum sound can be heard at certain height of the air column.

i) Name the type of waves produced in the air column

ii) what do you mean by beats?

iii) obtain an expression for best frequency.

Let’s try to make this a two way exercise. While we gather the question banks, you might have some inputs on this too! Please use the comments box below and post questions that you think are important from your analysis. It would help the HSE community a lot.

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