Answer: C

Explanation:

Gasohol is a cheaper alternative to fuel, which is prepared from sugarcane juice. Normal alcohol is prepared from sugarcane under gasohol. Pollution can be avoided by mixing this alcohol with petrol. Hence, statement 1 is correct.

According to K.K. Gandhi, a scientist at the Indian Petroleum Institute, the amount spent on petroleum in India and the increase in petroleum pollution can be reduced to a great extent by the use of gasohol. Hence, statement 2 is correct.

Gasohol fuel can be used in the engines of cars, motorcycles, scooters, etc. without making any changes. By using this fuel, environmental and ecological side effects can be avoided. By mixing alcohol made from sugarcane in petrol, emissions of hydrogen, carbon and carbon monoxide into the environment are almost eliminated and there is no problem like smoke and rumbling in the fuel. By using gasohol, fuel can be saved by 3 to 5 percent. Hence, statement 3 is correct.

Answer: B

Explanation:

Battery operated vehicles are driven by electric motors instead of petrol and diesel. In these vehicles, the motor receives electricity from recharged batteries. Hence, statement 1 is correct.

Battery operated vehicles provide environment friendly, pollution free and energy efficient sustainable transportation system. Expected improvements in technical efficiency are being achieved through research work in this area. Ministry of New and Renewable Energy (MNRE) is the nodal agency, integrating and coordinating State Departments and Union Territories for dissemination and promotion of VoV. Hence, statement 2 is correct.

Research and development projects related to highest capacity batteries for BOV such as nickel metal hydride, lithium ion, lithium polymer electrolyte batteries and super capacitors are being supported. Nickel metal hydride, developed for powering an electric scooter, has been demonstrated. Hence, statement 3 is incorrect.

Answer: B

Explanation:

Magneto hydrodynamics (MHD) is the principle of energy production based on the direct conversion of thermal energy into electrical energy. Right now this theory is still in the experimental stage. Intensive research on this technology is going on in Russia, United States of America, Japan, China, Netherlands, Australia, Poland and Finland. Hence, statement I is correct.

Through this technology, very high temperature (2800 Kelvin) is required to directly convert thermal energy into electrical energy by the flow of conducting fluid on the magnetic surface. In magneto hydrodynamics system, the generator is installed in a single unit without moving parts. In India, the Coal Based Magneto Hydrodynamics Research Project is being carried out at a 5 MW thermal power scale installed plant at Tiruchirappalli, Tamil Nadu. Hence, statement II is correct.

Here both statement and are correct and statement-II is not the correct explanation of statement-I. Hence, option (b) is correct.

Answer: C

Explanation:

Various types of radioactive rays are emitted from the nucleus of the atom of radioactive substances. There are three types of radioactive rays - alpha (α) rays, which were first discovered by Becquerel; beta (ẞ) rays, which were first discovered by Rutherford; and gamma (γ) rays, which were first discovered by Marie and Pierre Curie.

α -particle rays are made up of doubly ionized helium atoms. They can also be written as He+2. These rays are positively charged. Their velocity is a fraction of the velocity of light. They have the highest ionization power. These rays are affected by electric and magnetic fields. They contain two protons and two neutrons. Hence, pair 1 is correctly matched.

B-rays are made of electrons. These are negatively charged and get deposited in electric and magnetic fields. Their velocity is almost equal to the speed of light. Their ionization capacity is less than α-particles. These rays also produce fluorescence. Emission of ẞ-particles does not change the atomic weight. Due to emission of particles the atomic number increases by 1 and isobar elements are formed. Hence, pair 2 is correctly matched.

ẞ-rays are made up of electrons. They are negatively charged and get deposited in electric and magnetic fields. Their velocity is almost equal to the velocity of light. Their ionization capacity is less than that of α-particles. These rays also produce fluorescence. The emission of ẞ-particles does not change the atomic weight. The emission of its particles increases the atomic number by 1 and isobars are formed. Hence, pair 2 is correctly matched.

γ-rays are made up of photons. They do not have any charge. They are not affected by electric and magnetic fields. Their ionization power is very low. Their penetrating power is much higher than α and ẞ rays. Their velocity is equal to the velocity of light. They are similar to X-rays, but their wavelength is smaller. Hence, pair 3 is correctly matched.

Answer: C

Explanation:

There are some elements which cannot persist in their independent form in nature for long and they gradually get converted into other elements. It was discovered by Henri Becquerel that uranium metal and its salts emit a special type of invisible rays. These invisible rays affect the choreographic plate wrapped in collage paper and turn it black. Hence, statement 1 is correct.

These rays are so intense that they pass through even thin sheets of metal. Ionizes gases and produces fluorescence in zinc sulphide. These rays are called 'bacural rays'. Ultimately, the elements that emit circular rays are called radioactive elements and this property is called radioactivity. Hence, statement 2 is correct.

The radioactivity produced by showering alpha rays on some short stable elements is called artificial radioactivity. That is, bombarding an aluminum nucleus with alpha particles knocks out a neutron from the aluminum nucleus, resulting in a transformation of aluminum into a radioisotope of phosphorus. Hence, statement 3 is correct.