NCERT Solutions Class 9 Social Science Chapter 3 Preventing Common Human Induced Disaster

1. Why are nuclear bombs more hazardous than conventional bombs?

Answer. A nuclear bomb derives its destructive force from nuclear reactions of fission or a combination of fission and fusion. Nuclear bombs with a small yield are significantly more powerful than the largest conventional bombs. The amount of energy released from nuclear energy is enormous. Single weapon is capable of destroying an entire city. Nuclear bombs emit harmful radiations for a long period of time. It also affects the genes of the victim and its effects are thus passed on to generations.

2. Find at least 2 examples of common human induced disasters in your environment. Suggest how they can be reduced or removed.

Answer. Two common human induced disasters are terrorist’s attacks and road accidents. Ways to avoid terrorists attacks:

ii.   Call Police Control Room on Telephone No. 100. Every citizen has the right to call up.

iii.   After informing the police try to keep a watch on the suspected object and caution others to keep away from it.

iv.   Be alert of any suspicious person or parked vehicle.

Ways to avoid road accidents:

i.   Follow the traffic rules to avoid road accidents.

ii.      Avoid overtaking and over speeding.

iii.   Make sure there is availability of safety kits while travelling by rails, ships or aeroplanes.

iv.   Be aware of the safety measures to be taken during accidents.

v.   Organise ‘Traffic Safety Week’ in your school to spread awareness about traffic rules.

3. What are the common human-induced hazards in your locality which according to you have the likelihood of becoming a disaster? What are the five different steps that you would take to reduce their impact?

Answer. The common human induced hazards are fire and chemical accidents

Steps to be taken to reduce the impact of these disasters:

i. Spread awareness about the impact of these disasters

ii. Creating community preparedness

iii. Improving fire resistance, fire fighting capabilities and warning system

iv. Creating a resource map, both human and material. v. Limit storage capacity of the toxic substances

vi. Co-ordination with government hospital, NGOs, for training of disaster management

4. Why do radiation disasters affect a larger area than chemical disasters?

Answer. A radiation disaster affects a larger area than a chemical disaster because a chemical disaster is restricted only to the area where the chemical accident has occurred, while a radiation disaster spreads gaseous radioactive particles in the atmosphere, which can travel far and wide due to wind. In a chemical disaster, there is no chain reaction, while even a few radioactive particles can cause severe radiation effects as they work by a chain reaction.

5. How will you use the dates August 6 and August 9 to create awareness about the ill-effects of nuclear disasters?

6. What care must be taken for the disposal of biological waste from pathological laboratories and hospitals?

Answer. Biological waste is very harmful and should be disposed off carefully:

i. Mouth and nose should be covered while handling biological waste.

ii. Wearing of protecting gloves, laboratory coats and frequent hand washing are recommended while handling infectious waste.

iii. One should avoid remaining in long contact with such products.

v. Biohazardous waste should be separated from other types of waste before its disposal.

7. List 5 measures to protect yourself from nuclear radiation and attacks.

Answer. Measures to protect oneself from nuclear radiation and attacks:

i.   Do not panic

ii.   Do not gaze directly at the explosion.

iii.   Close all doors and windows (since, radioactivity cannot penetrate into solid structures).

iv.   Do not consume any food after the nuclear explosion. v.   Act according to the government’s instructions.

8. Study figure 1.1 and identify which natural disaster is most common and what parts of the Earth are most affected by it.

World distribution of disasters triggered by natural hazards

Answer. According to the given figure, floods are the most common natural disaster. Floods are more common in countries like India, Bangladesh and China. Floods mainly occur in the areas of high rainfall and the areas with large rivers