Please select a subject first
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Which type of telescope can be made using a concave mirror, convex mirror, plane mirror and a lens? Draw diagrams of these telescopes.
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Write briefly about the three methods of electrolysis of sodium chloride.
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Write the chemical formula.
common salt
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Write the uses of diamond.
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Write two physical properties.
Diamond
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Give scientific reasons.
The velocity of an object at rest is considered to be uniform.
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Give scientific reason.
The velocity of an object at rest is considered to be uniform.
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Give scientific reasons.
The velocity of an object at rest is considered to be uniform.
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Give scientific reason.
The velocity of an object at rest is considered to be uniform.
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Give scientific reason.
The velocity of an object at rest is considered to be uniform.
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Give scientific reason.
The velocity of an object at rest is considered to be uniform.
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- Take two aluminium channels of different lengths.
- Place the lower ends of the channels on the floor and hold their upper ends at the same height.
- Now take two balls of the same size and weight and release them from the top end of the channels. They will roll down and cover the same distance.
- At the moment of releasing the balls, which energy do the balls have?
- As the balls roll down which energy is converted into which other form of energy?
- Why do the balls cover the same distance on rolling down?
Note: The question is wrong. It should be "Why do the balls cover the same distance after rolling down"? - What is the form of the eventual total energy of the balls?
- Which law related to energy does the above activity demonstrate? Explain.
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If the energy of a ball falling from a height of 10 metres is reduced by 40%, how high will it rebound?
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The following table shows the current in Amperes and potential differences in Volts.
- Find the average resistance.
- What will be the nature of the graph between the current and potential difference? (Do not draw a graph.)
- Which law will the graph prove? Explain the law.
| V (volts) | I (amp) |
| 4 | 9 |
| 5 | 11.25 |
| 6 | 13.5 |
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Match the pairs.
| ‘A’ Group | ‘B’ Group |
| 1. Free electrons | a. V/R |
| 2. Current | b. Increases the resistance in the circuit |
| 3. Resistivity | c. Weakly attached |
| 4. Resistances in series | d. VA/LI |
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If a charge of 420 C flows through a conducting wire in 5 minutes what is the value of the current?
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Which criteria are used for the classification of plants? Explain with reasons.
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Explain in detail the inter-relationship between the food chain and the food web.
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Answer the following question in brief.
What is fermentation?
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Match the pairs.
| ‘A’ group | ‘B’ group |
| 1. Rhizobium | a. Food poisoning |
| 2. Clostridium | b. Nitrogen fixation |
| 3. Penicillium | c. Bakery products |
| 4. Yeast | d. Production of antibiotics |
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