English Medium कक्षा १० - CBSE Question Bank Solutions

A metal nitrate 'A' on heating gives a metal oxide along with evolution of a brown coloured gas 'B' and a colourless gas, which helps in burning. Aqueous solution of 'A' when reacted with potassium iodide forms a yellow precipitate.

1. Identify 'A' and 'B'
2. Name the types of the reactions involved in the above statement.

A person is unable to see clearly a poster fixed on a distant wall. He however sees it clearly when standing at a distance of about 2 m from the wall.

1. Draw ray diagram to show the formation of image by his eye lens when he is far away from the wall.
2. List two possible reasons of this defect of vision.
3. Draw ray diagram to show the correction of this defect using appropriate lens.

The resistance of a resistor is reduced to half of its initial value. If other parameters of the electrical circuit remain unaltered, the amount of heat produced in the resistor will become ______.

Observe the following diagram and answer questions following it: 

1. Identify the defect of vision shown.
2. List its two causes.
3. Name the type of lens used for the correction of this defect.

What is observed when silver chloride is exposed to sunlight? Give the type of reaction involved.

How is electric current related to the potential difference across the terminals of a conductor?

Draw a labelled circuit diagram to verify this relationship.

Why should an ammeter have low resistance?

One of the events that does not occur during photosynthesis is ______.

Vinita and Ahmed demonstrated a circuit that operates the two headlights and the two sidelights of a car, in their school exhibition. Based on their demonstrated circuit, answer the following questions.

1. State what happens when switch A is connected to:
   a) Position 2
   b) Position 3
2. Find the potential difference across each lamp when lit.
3. Calculate the current.
   a) in each 12 Ω lamp when lit.
   b) In each 4 Ω lamp when lit.
   OR
4. Show, with calculations, which type of lamp, 4.0 Ω or 12 Ω, has the higher power.

A small amount of copper oxide was taken in a beaker and dilute hydrochloric acid was added with continuous stirring of the solution. Name the compound formed and state the colour of its solution. Write the balanced chemical equation for the reaction that occurs. Based on the reaction, state the nature (acidic/basic) of copper oxide.

When lead nitrate is heated strongly in a boiling tube, two gases are liberated and a solid residue is left behind in the test tube.

1. Name the type of chemical reaction and define it.
2. Write the name and formula of the coloured gas liberated.
3. Write the balanced chemical equation for the reaction.
4. Name the residue left in the test tube and state the method of testing its nature (acidic/basic).

Write one equation for the decomposition reaction where energy is supplied in the form of light.

Write one equation for the decomposition reaction where energy is supplied in the form of electricity.

A solution of a substance ‘X’ is used for whitewashing.

1. Name the substance ‘X’ and write its formula.
2. Write the reaction of the substance ‘X’ named in the above formula with water.

\[\ce{Fe2O3 + 2Al -> Al2O3 + 2Fe}\]

The above reaction is an example of a ______.

What happens when dilute hydrochloric acid is added to iron fillings? Choose the correct answer.

Write the balanced chemical equation for the following and identify the type of reaction.

\[\ce{Magnesium(s) + Hydrochloric acid(aq) -> Magnesium chloride(aq) + Hydrogen(g)}\]

In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.

Make a diagram to show how hypermetropia is corrected. The near point of a hypermetropic eye is 1 m. What is the power of the lens required to correct this defect? Assume that the near point of the normal eye is 25 cm.

State the rule to determine the direction of a magnetic field produced around a straight conductor-carrying current.