English Medium Class 10 - CBSE Question Bank Solutions for Science

Write balanced chemical equation for the following word equation.

Lead nitrate + Potassium iodide → Lead iodide + Potassium nitrate

Is this a double displacement reaction? Justify your answer. Name the compound precipitated and write the ions present in it.

Write the method of preparation of Ca(OH)₂. What happens when CO₂ is passed through it? Write balanced chemical equation for the reaction involved.

Give an example of a double displacement reaction.

Define ‘redox reaction’. Give one example.

What is an oxidising agent?

Why does the colour of copper sulphate solution change when an iron nail is dipped in it?

Identify the substances that are oxidised and the substances that are reduced in the following reaction.

\[\ce{4Na(s) + O2(g) -> 2Na2O(s)}\]

Which of the statements about the reaction below are incorrect?

\[\ce{2PbO(s) + C(s) → 2Pb(s) + CO2(g)}\]

1. Lead is getting reduced.
2. Carbon dioxide is getting oxidised.
3. Carbon is getting oxidised.
4. Lead oxide is getting reduced.

 Explain the following in term Oxidation of gain or loss of oxygen with two example.

A shiny brown-coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black-colored compound formed.

Judge the equivalent resistance when the following are connected in parallel − (a) 1 Ω and 10⁶Ω, (b) 1 Ω and 10³Ω and 10⁶Ω.

A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R’, then the ratio `"R"/"R'"` is ______.

A battery of 9 V is connected in series with resistors of 0.2 Ω, 0.3 Ω, 0.4 Ω, 0.5 Ω and 12 Ω, respectively. How much current would flow through the 12 Ω resistor?

Why is the series arrangement not used for domestic circuits?

Consider a circular loop of wire lying in the plane of the table. Let the current pass through the loop clockwise. Apply the right-hand rule to find out the direction of the magnetic field inside and outside the loop.

The magnetic field in a given region is uniform. Draw a diagram to represent it.

The magnetic field inside a long straight solenoid-carrying current ______.

Which of the following property of a proton can change while it moves freely in a magnetic field? (There may be more than one correct answer.)

Which of the following property of a proton can change while it moves freely in a magnetic field? (There may be more than one correct answer.)

A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is ______.