1) Does pure water conduct electricity? If not, what can we do to make it conducting?
क्या शुद्ध जल विद्युत का चालन करता है? यदि नहीं तो इसे चालक बनाने के लिए हम क्या कर सकते हैं।
22) Explain why a charged body loses its charge of we touch it with our hand
जब हम किसी आवेपित वस्तु को हाथ से छूते हैं तो वह अपना आवेश खो देती है, व्याख्या कीजिए।
23) Sometimes, a crackling sound is heard while taking off a sweater during winters. Explain
सर्दियों में स्वेटर उतारते समय चट-चट की ध्वनि सुनाई देती है। व्याख्या कीजिए।
24) Suggest three measures to protect ourselves from lighting,
तड़ित से अपनी सुरक्षा के तीन उपाय सुझाइए।
25) State the laws of reflection,
परावर्तन के नियम बताइए।
26) Explain how you can take care of your eyes.
वर्णन कीजिए की आप अपने नेत्रों की देखभाल कैसे करेंगे।
27) What is metamorphosis?
कायांतरण किसे कहते हैं?
Bunlain the imnortance of reproduction in organisms
Answers
Answer:
1) Pure water or distilled water does not conduct electricity because it doesn't contain salts in it. To make it conducting, we add a pinch of common salt since salt solutions are good conductors of electricity.
22) Human body is a conductor of electricity. So, when we touch a charged object, our body conducts its charges to the Earth. That is why a charged body loses its charge, if we touch it with our hand. This phenomenon is known as earthing.
23) Sweaters are made up of wool , which is a poor conductor of electricity. When we are wearing the sweater the wool is in contact with our body, there is friction as there is rubbing between the body and the wool. ... due to this force, we hear the crackling sound while taking off the sweater during winters.
24) Avoid water during a thunderstorm. Lightning can travel through plumbing.
Avoid electronic equipment of all types. Lightning can travel through electrical systems and radio and television reception systems.
Avoid corded phones.
25) (i) The incident ray, the reflected ray and the normal ray at the point of incidence, lie in the same plane. (ii) The angle of incidence is equal to the angle of reflection.
26) Wash your eyes with clean cold water.
Do not use too bright or too dim light while reading or doing work. ...
Avoid reading in a moving vehicle.
Never rub your eyes if something gets inside. ...
Self-treatment could be dangerous to the eyes. ...
Good nutrition is very important for both your general and eye health.
27) The transformation of the larva into an adult through drastic changes is called metamorphosis. Metamorphosis is a biological process which involves sudden and abrupt changes in the body structure of the animal by cell growth and differentiation. It is generally observed in amphibians and insects.
28) Reproduction maintains a balance between the birth rate and death rate. The new individuals replace the old and the dying population. It also helps in increasing the number of species in the ecosystem.