English Medium Class 10 - CBSE Question Bank Solutions for Science

Which of the following statements is correct regarding the propagation of light of different colours of white light in air?

Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?

The bluish colour of water in deep sea is due to

The diagram above is a schematic diagram of a household circuit. The house shown in the above diagram has 5 usable spaces where electrical connections are made. For this house, the mains have a voltage of 220 V and the net current coming from the mains is 22A.

1. What is the mode of connection to all the spaces in the house from the mains?
2. The spaces 5 and 4 have the same resistance and spaces 3 and 2 have respective resistances of 20Ω and 30Ω. Space 1 has a resistance double that of space 5. What is the net resistance for space 5.
3. What is the current in space 3?
4. What should be placed between the main connection and the rest of the house’s electrical appliances to save them from accidental high electric current?

Three resistors of 6Ω, 4Ω and 4Ω are connected together so that the total resistance is 8Ω. Draw a diagram to show this arrangement and give reason to justify your answer.

Two V-I graphs A and B for series and parallel combinations of two resistors are as shown. Giving reason state which graph shows (a) series, (b) parallel combination of the resistors.

When light enters the atmosphere it strikes extremely fine particles, which deflect the rays of light in all possible directions, This is due to ______.

A piece of wire of resistance R is cut into three equal parts. These parts are then connected in parallel. If the equivalent resistance of this parallel combination is R₁, what is the value of the ratio R₁ : R?

When a beam of white light passes through a region having very fine dust particles, the colour of light mainly scattered in that region is ______.

Name the phenomenon of light responsible for Tyndall effect. Write an event where this phenomenon can be observed.

Study the following circuit:

On the basis of this circuit, answer the following questions:

i. Find the value of total resistance between the points A and B.

ii. Find the resistance between the points B and C.

iii. Calculate the current drawn from the battery, when the key is closed

OR

iii. In the above circuit, the 16Ω resistor or the parallel combination of two resistors of 8 Ω, which one of the two will have more potential difference across its two ends? Justify your answer.

State any four characteristics of a homologous series

Write the next homologue of the following: C₂H₄

Write the next homologue of the following: C₄H₆

What is meant by homologous series of carbon compounds?

Classify the following carbon compounds into two homologous series and name them.

C₃H₄, C₃H₆, C₄H₆, C₄H₈, C₅H₈, C₅H₁₀

Write the name and formula of the 2nd member of homologous series having general formula C_nH_2n.

Write the name and formula of the 2nd member of homologous series having general formula C_nH_{2n + 2}.

Write the name and formula of the 2nd member of homologous series having general formula C_nH_{2n – 2}.

Write the molecular formula of two consecutive members of homologous series of aldehydes. State which part of these compounds determines their

1. physical and 
2. chemical properties