English Medium कक्षा १० - CBSE Question Bank Solutions for Science

You are given the following chemical equation:

Mg (s) + CuO (s) → MgO (s) + Cu (s)

This equation represents:
(a) decomposition reaction as well as displacement reaction
(b) combination reaction as well as double displacement reaction
(c) redox reaction as well as displacement reaction
(d) double displacement reaction as well as redox reaction

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

\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]

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

The colours of aqueous solutions of CuSO₄ and FeSO₄ as observed in the laboratory are:

(A) pale green and light blue respectively

(B) light blue and dark green respectively

(C) dark blue and dark green respectively

(D) dark blue and pale green respectively

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

Oxidation

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

Reduction

Name and state the rule of determine the direction of force experienced by a current carrying straight conductor placed in a uniform magnetic field which is perpendicular to it. 

Answer the following question.
While studying the dependence of potential difference ( V) across a resistor on the current (I) passing through it, in order to determine the resistance of the resistor, a student took 5 readings for different values of current and plotted a graph between V and t. He got a straight line graph passing through the origin. What does the straight-line signify? Write the method of determining the resistance of the resister using this graph. 

Two bulbs of 100 W and 40 W are connected in series. The current through the 100 W bulb is 1 A. The current through the 40 W bulb will be ______.

The following diagram shows two parallel straight conductors carrying the same current. Copy the diagram and draw the pattern of the magnetic field lines around them showing their directions. What is the magnitude of the magnetic field at a point 'X' which is equidistant from the conductors? Give justification for your answer.

Rusting of iron involves a chemical reaction which is a combination of:

Which of the following statements about the given reaction are correct?

\[\ce{3Fe_{(s)} + 4H2O_{(g)} -> Fe3O4_{(s)} + 4H2_{(g)}}\]

(i) Iron metal is getting oxidised.

(ii) Water is getting reduced.

(iii) Water is acting as the reducing agent.

(iv) Water is acting as oxidising agent.

Oxidation is a process which involves ____________.

The process of reduction involves ____________.

\[\ce{MnO2 + 4HCl -> + 2H2O + Cl2}\]

Identify the substance oxidized in the above equation.

When Ag is exposed to air it gets a black coating of ____________.

Select the oxidising agent for the following reaction:

\[\ce{H2S + I2 -> 2HI + S}\]

In the reaction of iron with copper sulphate solution:

CuSO₄ + Fe → Cu + FeSO₄

Which option in the given table correctly represents the substance oxidized and the reducing agent?

Two wires of the same length and area made of two materials of resistivity ρ₁ and ρ₂ are connected in series to a source of potential V. The equivalent resistivity for the same area is:

If R₁ and R₂ be the resistance of the filament of 40 W and 60 W respectively operating 220 V, then: