Exploring Forces — Science STD 8 — Question

For electroplating copper on an iron object, which terminal of the battery (positive or negative) is connected to the iron object? Also name the electrolyte you will use for this purpose.

How can a very heavy machine be moved conveniently from one place to another in a factory? (No crane is available for this purpose).

Although wood has a very high calorific value, we still discourage its use as a fuel. Explain.

Given below is a conversation between two farmers Heera and Beera.
Heera: Brother Beera, your maize crops look beautiful. They have grown pretty fast.
Beera: Yes, I have sprayed urea this time. What about you ?
Heera: Well, I am still relying on good old cow dung. I am saving money for buying a tractor.
Beera: That's good. Tractor saves a lot of time and labour.
Heera: Yes, it's been very labour intensive for me and now these weeds have come up.
Beera: Try weedicides, they are very effective.
Now, answer the following questions.
(i) List the practices which are not environment friendly and why ?
(ii) What is the advantage of modern agricultural Implements over traditional ones ?
(iii) Name one weedicide and the precaution, farmers must take during its application.

Briefly mention, which of the following will cause regular reflection of light and which diffuse reflection of light. Polished wooden table.

What happens when an inflated balloon is kept without closing its mouth?

Explaining briefly about seismic zones.