Everyday Science—Questions and Answers

Everyday Science—Questions and Answers

1. Why does a piece of iron get rusted if left exposed in the open?

Answer: Iron piece rusts if left exposed in the open because it reacts with the oxygen in the air, forming iron oxide—a compound of Iron and oxygen. 

2. Why can petrol fire not be put out with water?

Answer: Petrol is a hydro carbon which remains isolated with water and is having less density. So when water is poured petrol floats on it and keeps on burning. The temperature of the burning petrol is so high that the water poured on the petrol fire is evaporated before it extinguishes the fire. 

3. Ice packed is saw dust does not melt quickly. Why?

Answer: Saw dust is a bad conductor of heat and protects the ice from the external heat and hence from melting away quickly. 

4. White light passing through a glass prism gives rise to a coloured pattern on the wall. Why?

Answer: White light is made up of seven colours. Rays of different colours refract or bend along different paths and fall on different points on the wall forming a coloured pattern known as spectrum. 

पत्र-लेखन (Letter-writing)

हिन्दी : पत्र-लेखन (Letter-writing)

दूर रहने वाले अपने सबन्धियों अथवा मित्रों की कुशलता जानने के लिए तथा अपनी कुशलता का समाचार देने के लिए पत्र एक साधन है। इसके अतिरिक्त्त अन्य कार्यों के लिए भी पत्र लिखे जाते है।

पत्र का महत्व

As keys do open chests.
So letters open breasts .

उक्त अँगरेजी विद्वान् के कथन का आशय यह है कि जिस प्रकार कुंजियाँ बक्स खोलती हैं, उसी प्रकार पत्र (letters) ह्रदय के विभित्र पटलों को खोलते हैं। मनुष्य की भावनाओं की स्वाभाविक अभिव्यक्ति पत्राचार से भी होती हैं। निश्छल भावों और विचारों का आदान-प्रदान पत्रों द्वारा ही सम्भव है। पत्रलेखन दो व्यक्तियों के बीच होता है। इसके द्वारा दो हृदयों का सम्बन्ध दृढ़ होता है। अतः पत्राचार ही एक ऐसा साधन है, जो दूरस्थ व्यक्तियों को भावना की एक संगमभूमि पर ला खड़ा करता है और दोनों में आत्मीय सम्बन्ध स्थापित करता है। पति-पत्नी, भाई-बहन, पिता-पुत्र- इस प्रकार के हजारों सम्बन्धों की नींव यह सुदृढ़ करता है। व्यावहारिक जीवन में यह वह सेतु है, जिससे मानवीय सम्बन्धों की परस्परता सिद्ध होती है। अतएव पत्राचार का बड़ा महत्व है।

Cyrus Pallonji Mistry

Cyrus Pallonji Mistry

Cyrus Pallonji Mistry was born on 4th July, 1968. He is an Irish businessman who recently became chairman of Tata Group. He is the sixth chairman of the group and the second not to be named Tata. Mistry is often described as "soft-spoken, candid and down to earth" personality. He is fond of cars and horse racing. However, he is known to be a foodie and his favorite holiday destination is Europe.

Mistry considers himself to be of Irish nationality as his mother is Irish by birth, although his father is Indian-born. Mistry is married to Rohiqa Chagla and has two sons.

Childhood

Cyrus Mistry is the youngest son of Pallonji Mistry, an Irish-Parsi construction tycoon. In the 1930s, Mistry's grandfather first bought shares in Tata Sons, which as of November 2011, stood at 18.5 percent, making him the largest single shareholder in a firm.