Science

A. IN-TEXT ACTIVITIES Activity 12.1 Question (text from the book): “Take a used ballpen refill and rub it vigorously with a piece of polythene. Bring it close to small pieces of paper. Take care not to touch the rubbed end of the refill with your hand or with a metallic object. Repeat the activity with … Read more

 A) IN-TEXT QUESTIONS AND ACTIVITIES Activity 13.1 Question (as described in the text): You fix a white sheet of paper on a board. Take a comb and cover all its openings except one in the middle. Shine a torch through the open space so that a narrow beam of light falls on the sheet of … Read more

Activity 11.1 Question: “However, if the bulb does not glow, it means that the tester is not working. Can you think of the possible reasons?” Answer: The bulb may not glow if the connections are loose, if the bulb is fused, or if the cells in the tester have no power left. Tightening the connections, … Read more

In-text Questions and Answers: 1. What is the name of the period between childhood and adulthood? Answer: The period between childhood and adulthood is called adolescence. 2. Why do some body parts seem out of proportion during adolescence? Answer: During adolescence, different parts of the body grow at different rates. This means your arms or … Read more

In-Text Questions and Answers Question: How do you come to know that a ‘period’ is over in your school? Answer: We know that a period is over when we hear the school bell ring. Question: How is sound produced? How does it travel from one place to another? How do we hear sound? Why are … Read more

1. Fill in the blanks. (a) Friction opposes the motion between the surfaces in contact with each other. (b) Friction depends on the nature of surfaces. (c) Friction produces heat. (d) Sprinkling of powder on the carrom board reduces friction. (e) Sliding friction is less than the static friction. 2. Four children were asked to … Read more