Explore topic-wise InterviewSolutions in Current Affairs.

Four ways for the judicious use of energy:

(a) The fossil fuels such as coal, petroleum, natural gas should be used only for the limited purposes when there is no other alternative source of energy available.

(b) The wastage of energy should be avoided.

(c) Efforts must be made to make use of energy for community or group purposes.

(d) The cutting of trees must be banned and more and more new trees must be roped to grow.

Renewable source of energy is-

(d) Sun

The ultimate source of energy is-

(d) Sun

(i) Tidal energy: The energy possessed by rising and falling water in tides is known as tidal energy.Dams are constructed across a narrow opening to the sea to harness tidal energy and produce electricity. However, it is not a major source of energy as the rise and fall of seawater during tides is not enough to generate electricity on a large scale.

(ii) Ocean energy: Water in the oceans possesses energy in two forms:

(a) Ocean thermal energy- The energy available due to the difference in temperature of water at the surface and at deeper levels of ocean is called the ocean thermal energy. This energy is harnessed for producing electricity by a device called ocean thermal energy conversion power plant (OCTEC power plant).

(b) Oceanic waves energy- The kinetic energy possessed by fast moving oceanic (or sea) waves is called oceanic waves energy. Though models have been made to generate electricity from oceanic waves, but so far it has not been put to practical use.

(iii) Geo thermal energy: The heat energy possessed by the rocks inside the Earth is called geothermal energy.

The hot rocks present at the hot spots deep inside the Earth, heat the underground water and turn it into steam. This steam is compressed at high pressure between the rocks. Holes are drilled deep into the Earth up to the hot spots to extract the steam through pipes, which is utilized to rotate the turbines connected to the armature of an electric generator to produce electricity.

Advantages of producing the hydroelectricity:

1. It does not produce any environmental pollution.

2. It is a renewable source of energy.

Disadvantages of producing hydroelectricity:

1. Due to the construction of dams over the rivers, plants and animals of that place get destroyed or killed.

2. The ecological balance in the downstream areas of rivers gets disturbed.

(a)Light energy into electrical energy

(b)Mechanical energy into electrical energy.

(c)Mechanical energy into electrical energy.

(d)Nuclear energy(or heat energy) into electrical energy.

Sun is the main source of energy on earth.

Advantages of using nuclear energy:

1. A very small amount of nuclear fuel can produce a tremendous amount of energy.

2. Once the nuclear fuel is loaded into nuclear power plant, it continues to release energy for several years.

Disadvantages of using nuclear energy:

1. It is not a clean source of energy because very harmful nuclear radiations are produced in the process.

2. The waste causes environmental pollution.

When a heavy nucleus is bombarded with slow neutrons, it splits into two nearly equal light nuclei with a release of tremendous amount of energy. In this process of nuclear fission, the total sum of masses of products is less than the total sum of masses of reactants. This lost mass gets converted into energy. The energy so released is called nuclear energy.

Principle: The heat energy released due to the controlled chain reaction of nuclear fission of uranium-235 in a nuclear reactor is absorbed by the coolant which then passes through the coils of a heat exchanger containing water. The water in heat exchanger gets heated and converts into steam. The steam is used to rotate the turbine which in turn rotates the armature of a generator in a magnetic field and thus produces electricity.

Advantages of using solar panels:

1. They do not cause any pollution in the environment.

2. Running cost of solar panel is almost zero.

3. They last over a long period of time.

4. They do not require any maintenance.

5. They are suitable for remote and inaccessible places where electricity power lines cannot be laid.

Disadvantages of using solar panels:

1. The initial cost of a solar panel is sufficiently high.

2. The efficiency of conversion of solar energy to electricity is low.

3. A solar panel produces d.c. electricity which cannot be directly used for many household purposes.

Advantages of using the wind energy:

1. It does not cause any kind of pollution.

2. It is an everlasting source.

Disadvantages of using wind energy:

1. The establishment of a wind farm is expensive.

A large area of land is needed for the establishment of a wind farm.

The kinetic energy possessed by the flowing water is called the water or hydro energy. Principle of a hydroelectric power plant is that the water flowing in high altitude rivers is collected in a high dam (or reservoir). The water from dam is then allowed to fall on a water turbine which is located near the bottom of the dam. The shaft of the turbine is connected to the armature of an electric generator or dynamo.

At present only 23% of the total electricity is generated by the hydro energy.

The energy obtained from sun is called the solar energy. A solar power plant is a device in which heat energy of sun is used to generate electricity. It consists of a large number of concave reflectors, at the focus of which there are black painted water pipes. The reflectors concentrate the heat energy of the sun rays on the pipes due to which water inside the pipes starts boiling and produces steam. The steam thus produced is used to rotate a steam turbine which drives a generator producing electricity.

The kinetic energy of the moving large masses of air is called the wind energy. Wind energy is used in a wind generator to produce electricity by making use of wind mill to drive a wind generator.

At present in India, more than 1025MW electric power is generated using the wind energy.

At present only about 3% of the total electrical power generated in India is obtained from the nuclear power plants.

Tarapur in Maharashtra and Narora in Uttar Pradesh are the places where electricity is produced by use of nuclear energy

To prevent elevator from falling freely under gravity.

From the fig; R = mg cosθ

F = μR = μmg cosθ

Net force on the block down the incline,

= mg sinθ - F = mg sinθ - μmg cosθ

= mg(sinθ - μ cosθ)

Distance moved, x = 10 cm = 0.1 m

In equilibrium, work done = P.E. of the streched spring

Hence, mg(sinθ - m cosθ) × x = 1/2 kx²

⇒ 2 mg(sinθ - μ cosθ) = kx

⇒ 2 × 1 × 10(sin 37º - μ cos 37º) = 100 × 0.1

⇒ 20(0.601 - μ × 0.798) = 10

μ = 0.126

Is there then a dissipation of energy, Yes, No.

(a) Magnitude of acceleration, when just released is maximum.

(c) Speed is maximum when mass is at equilibrium position.

(a) (iii), 

(b) (ii), 

(c) iv, 

(d) (i)

(b) speed of ball changes every 10 seconds.

(c) average speed of ball over any 20 second interval is fixed.

(d) the acceleration of ball is the same as from the train.

Disobeying rules leads to punishment.

Correct answer is (b) seed coat

Correct option is (c) Secondary nucleus and endosperm

Correct option is (a) Geitonogamy

Diarrhoea, worms, hepatitis.

(i) Reproduction is the process by which offspring is produced which resembles the parents.

(ii) Morphologically and genetically identical individuals are called clones.

(iii) The part of the stem containing more than one bud which is joined onto a rooted plant.

(iv) Stock is a rooted plant on which part of the stem (scion) is joined in grafting.

People in a democratic country expect the government to work for their welfare.

The court asked the State Government to give Hakim Sheik the money that he had spent on his treatment.

Correct answer is (d) protandry

The court said that the difficulty that Hakim Sheik had to face could have cost him his life. If a hospital cannot provide timely medical treatment to a person, it means that the protection of life is not being given. The court also said that it was the duty of the government to provide the necessary health services, including treatment in emergency situations. Hospitals and medical staff must fulfil their duty of providing essential treatment. As various government hospitals refused to admit him, the State Government was asked to give Hakim Sheik the money that he had spent on his treatment

(i) The process in which each microspore mother cell divides meiotically to form tetrad of haploid microspores (pollen grains).

(ii) It is the ability of pollen grains to germinate and develop into male gametophyte.

(iii) Pollination is the transfer of pollen grains from anther to the stigma of flower.

(iv) Autogamy is a type of pollination in which bisexual flower is pollinated by its own pollen grains.

Ranjan got costly medical treatment.

(i) Dioecism is condition in which the plant bears either male or female flower and it is also called unisexuality.

(ii) The process of fertilization where both the male gametes participate in the complex fertilization mechanism seen in angiosperms is called double fertilization.

(iii) The process of development of zygote into an embryo is called embryogenesis.

(iv) Structural or physiological adaptive mechanism for survival is called dormancy.

(v) The condition in which there is development of more than one embryo inside the seed is called polyembryony.

It is because women’s health concerns are considered to be less important than the health of men in the family.

(a) To increase fertility of soil

Hakim Sheik filed a case in the court because of the indifferent attitude of various government hospitals that refused to admit him.

The government can take steps to provide healthcare for all by:

*   Increasing the number of hospitals, healthcare centres and family welfare centres.
*   Organising free camps for check up of general public.
*   Organising Pulse Polio campaigns.

*   Spreading health awareness among common people through different means. Workshops, seminars and training camps can also prove to be effective ways.

The negative aspects of healthcare in India are:
(a) Rural people face the crisis of doctors, because most doctors settle in urban areas. They have to travel long distances to reach a doctor.
(b) About live lakh people die from tuberculosis every year. Almost two million cases of mal aria are reported every year.
(c) Clean drinking water is not available to all. As a result poor people easily become prey to various waterborne diseases such as diarrhoea worms, hepatitis etc.
(d) Half of all children in India do not get adequate food to eat and are undernourished.

1. erosion 

2. plantation 

3. Bharatpur 

4. 1st July, 2014

The dead and decomposed organic matter present in the upper layer of soil is called humus.

The common definition of health is the ability of a person to remain free of illness and injuries. But health is not only about disease. It is something more than that. Apart from disease, we need to think of other factors such as safe drinking water, clean surroundings etc. because they affect our health in various ways. If people fail to get these basic amenities of life, they will fall ill. Being active and in good spirits are also essential part of health. We also need to be without mental stress, because we cannot be healthy for a long time if we are under mental strain.

Poor people are more likely to fall ill because they are not provided basic necessities like drinking water, adequate housing, clean surroundings, etc.