Wednesday, 13 August 2014

Chapter 12. Electricity | CBSE Class 10th Science | Solved Exercises

Multiple Choice Questions - MCQs : Chapter 12. Electricity | CBSE Class 10th Science


Question 1. What happens to the resistance of circuit if current through it is doubled ?
(a) Resistance is doubled
(b) Resistance becomes half
(c) Resistance remains same
(d) None

Answer. (c) Resistance remains same

Question 2. The work done in moving a unit positive charge, across two points in an electric circuit is measure of _____ ?
(a) Current
(b) Potential Difference
(c) Resistance
(d) Power

Chapter 3 Drainage | Geography | CBSE Class 9th | Solved Exercises

Question 1. Choose the right answer from the four alternatives given below:

(i) Which one of the following describes the drainage patterns resembling the branches of a tree?

(a) Radial
(b) Dendritic
(c) Centrifugal
(d) Trellis

Answer : (b) Dendritic


Chapter 13. WHY DO WE FALL ILL | CBSE Class 9th Science | Solved Exercises

Intext Questions | Page 178

Question 1. State any two conditions essential for good health.

Answer : A good health is ideally a state of well-being physically, mentally and socially . The two conditions essential for good health are:
  1. All community members must have access to basic and better health care facilities supported by the qualified medical professionals.
  2. There should be good economic opportunities for all. Community members should be socially well connected for any support or sharing of resources and should have high level of cleanliness and hygiene at personal or community level


Saturday, 5 July 2014

Exercise 1.3 Real Numbers | CBSE Class 10th Mathematics | Solutions

Question 1. Prove that √5 is irrational.

Solution : Let us assume, to the contrary, that √5 is rational.
That is, we can find integers a and b (≠ 0) such that :
a
√5=
b
Suppose a and b have a common factor other than 1, then we can divide by the common factor, and assume that a and b are coprime.
So, b √5 = a⋅

Friday, 4 July 2014

Real Numbers - Exercise 1.2 | CBSE Class 10th Mathematics | Solutions

Question 1. Express each number as a product of its prime factors:
(i) 140   (ii) 156    (iii) 3825   (iv) 5005    (v) 7429


Solution (i) To express the given number 140 as product of its prime factors, we employ the division method as shown below :

2|140
2|70
5|35
7|7
|1

∴ 140 = 2×2×5×7
       = 22×5×7


Thursday, 3 July 2014

Real Numbers - Exercise 1.1 | CBSE Class 10th Mathematics | Solutions

Points to remember

  • An algorithm is a series of well defined steps which gives a procedure for solving a type of problem. The word algorithm comes from the name of the 9th century Persian mathematician al-Khwarizmi.
  • A lemma is a proven statement used for proving another statement.
  • Euclid’s Division Lemma : Given positive integers a and b, there exist unique integers q and r satisfying a = bq + r, 0 ≤ r < b.
  • Euclid’s division algorithm : Euclid’s division algorithm is a technique to compute the Highest Common Factor (HCF) of two given positive integers. This is based on Euclid’s division lemma. According to this, the HCF of any two positive integers c and d, with c > d, is obtained as follows:

Friday, 4 April 2014

10th - Science | Solved Exercises

This post contains links to solutions of all chapters for NCERT textbook of Science for Class 10th under CBSE. Each link for the chapter provides solutions to questions given in its main exercises including multiple choice questions, numericals, activities and in-text questions given after a main section to check the under standing of  the topic by students .

Monday, 31 March 2014

CBSE Class 10th Science | Chapter 16. Management of Natural Resources | Solved Exercises

In Text Questions | Page 269 |Chapter 16. Management of Natural Resources | CBSE Class 10th Science |  

Question 1. What changes can you make in your habits to become more environment-friendly?

Answer. We can make certain positive changes in our habits to become more environment-friendly. We can follow the simple policy of the three R's i.e., Reduce, Reuse and Recycle
 Which simply means that for our living,

Saturday, 29 March 2014

CBSE Class 10th Science | Chapter 15. Our Environment | Solved Exercises

In Text Questions | Page 257 |Chapter 15. Our Environment | CBSE Class 10th Science

Question 1. Why are some substances biodegradable and some non-biodegradable?

Answer. Some substances can be acted upon by the micro organisms and broken down into simple substances. Such substances are called biodegradable.
Some substances are inert and cannot be acted upon by the microorganisms and do not breakdown into simple substances. Such substances are called non- biodegradable.

CBSE Class 10th Science | Chapter 14. Sources of Energy | Solved Exercises

Question 1. A solar water heater cannot be used to get hot water on
(a) a sunny day.
(b) a cloudy day.
(c) a hot day.
(d) a windy day.

Answer. (b) a cloudy day.