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A simple microscope is used by watch repairers. Give reason.
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Define Radius of curvature of the spherical mirror
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Define the Focal length of a spherical mirror
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What is corrosion?
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Compare roasting and calcination.
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A stone is thrown vertically upwards with initial velocity u reaches a height ‘h’ before coming down. Show that the time taken to go up is the same as the time taken to come down.
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An object thrown vertically upwards reaches a height of 500 m. What was its initial velocity? How long will the object take to come back to the earth? Assume g = 10 m/s2
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Observe the following picture a write down the chemical reaction with the explanation.

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Write a scientific reason.
Metallic character goes on decreasing while going from left to right in a period.
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Write scientific reasons.
Lemon or tamarind is used for cleaning copper vessels turned greenish.
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Solve the problem.
If the mass of a planet is eight times the mass of the Earth and its radius is twice the radius of the Earth, what will be the escape velocity for that planet?
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What will be the weight of a person on earth, who weighs 9N on the moon?
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A ball falls off a table and reaches the ground in 1 s. Assuming g=10 m/s2, calculate its speed on reaching the ground and the height of the table.
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Complete the process of iron rusting by filling the blanks. Suggest a way to prohibit the process.
The iron rust is formed due to........................... reaction. Different
regions on iron surface become anode and cathode.
Reaction on anode region :
`F_e(s) → Fe^(2+) (aq) +2e^-`
Reaction on anode region :
`O_2(g) + 4H^+(aq) +............................ → 2H_2 O (l) `
When Fe2+ ions migrate from anode region they react with ................... to form Fe3+ ions.
A reddish coloured hydrated oxide is formed from ............... ions. It is called rust.
`2Fe_(3+) (aq) + 4H_2O(l) → ................. + 6H_+(aq) `
A way to prevent rusting ..................................................................
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i) If g = GM/r2 then where will the value of g be high at Goa Beach or on top of Mount Everest?
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iii) Observe the figure and answer the following questions.
a) Identify the block shown by box A and write an electronic configuration of any one element of this block.
b) Identify the block of element denoted by letter B and write its period number.
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Identify the process shown in the diagram and explain it in short

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For freely falling object we can write the Newton’s second equation of motion as …..
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Answer the following question.
a) What is meant by corrosion?
b) Write names of any two methods of prevention of corrosion.
c) In which method, metal like copper, aluminium are coated with a thin layer of their oxides by means of electrolysis.
d) Explain this method with diagram.
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Find the odd man out:
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