Question : The mass number of elements P, Q, R are 2, 180, 235 respectively which one of them is most suitable to make a hydrogen bomb?
a. P only
b. P and Q both
c. Q only
d. Q and R both
Answer : A
Explanation: The first barrier to building a nuclear weapon is finding nuclear fuel. Very few types of atoms are both the right size and abundant enough to make a nuclear weapon. It's either uranium or plutonium for fission bombs, or a mixture of deuterium and tritium (both of them rare forms of hydrogen whose mass number is 2) for nuclear fusion.
Question : Which of the following acts as control rods in Nuclear reactor?
a. D2O
b. cadmium rod
c. Boron rod
d. Both cadmium rod and Boron rod
Answer : C
Explanation: Control rods are used in nuclear reactors to control the fission rate. Boron, silver, Indium and cadmium are capable of absorbing many neutrons without themselves fissioning, So they are used
Question : What is a good fuel?
Answer : A good fuel is that which release more heat on burning, It should be easily available, it should be economical and should not cause environmental pollution.
Question : The cost of production of electricity in a thermal power station located in Bihar/ Jharkhand/ Odisha is lesser than in Gujarat/Maharashtra. Do you agree? Justify your answer.
Answer : Yes, it is because in Bihar/Jharkhand/Odisha coal for thermal power plant is easily available whereas it has to be transported to Gujarat/Maharashtra for thermal power plant.
Question : Give some uses and advantages of solar energy.
Answer : Uses:
i. For cooking food in a solar cooker.
ii. For heating water in solar geysers.
iii. For generating electricity in space satellites, calculators, watches, etc., by solar cells and solar panels
iv. For generating electricity on a large scale by a solar power plant.
v. To melt metals in solar furnaces.
Advantages:
i. It does not cause any pollution.
ii. It is a renewable source of energy.
iii. It is free of cost.
Question : Can any source of energy be pollution free ? Why
Answer : No source of energy can be perfectly pollution free but bio-mass energy, hydroenergy, wind energy, geothermal energy, solar energy is almost pollution free. If fossil fuel is allowed to burn in presence of excess of oxygen, the pollution produced can be very much reduced.
Question : What are the environmental consequences of using fossil fuels? Suggest the steps to minimise the pollution caused by various sources of energy including nonconventional sources of energy causing global warming.
Answer : The pollution caused by burning of fossil fuels can be reduced by increasing the efficiency of the combustion process. Also, by using various techniques to reduce the escape of harmful gases and ashes into the surroundings. Along with the direct use of fossil fuels for various purposes like cooking and transport, these are majorly used for generating electricity.
Various techniques to reduce the escape of harmful gases and Environmental consequences of using fossil fuels are:
Steps to minimize the pollution are:
i. They are the largest emitters of greenhouse gases such as carbon dioxide and methane.
ii. Extraction of conventional fuels threatens the ecological balance in many areas.
iii. These fuels cause environmental problems.
iv. The dependency on fossil fuels should be reduced by switching to alternate sources of energy.
v. The judicious use of energy by avoiding wastage can reduce environmental problems.
vi. Regular servicing of energy conversion devices should be done in order to maintain their efficiency.
vii. We should focus on developing technology that could make the energy conversion devices much more efficient and cleaner.
viii. Research should be continued to produce long-lasting devices so that the environmental damage caused by assembly of devices gets minimized.