Questions for Gravitation (JC) Set 1

Imagine if the Moon doubles in mass, which of the following is likely to happen? Each month will be longer than 30 days. Nights will be a lot brighter since the Moon is nearer to the Earth Each day will be longer since the period of the Moon increases. The Moon continues to revolve around the Earth in the same …

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Gamma Rays

Gamma Rays They are electromagnetic waves of wavelengths shorter than those of X-rays Electrically neutral, are not deflected by electric and magnetic fields. Among the three types of radiation, gamma rays have the strongest penetration power. Gamma rays are stopped by lead of a few centimetres thick Ionisation power of gamma rays is about 1/10 000 that of alpha particles …

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Beta Particles

Beta Particles They are electrons with energy of a few MeV. Originated in the nucleus through a nuclear transformation in which a neutron changes to proton and an electron. Have high speeds, up to 50% the speed of light Easily deflected by a magnetic field and electric field Ionising power of beta particles is about 1/10 that of alpha particles. …

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Alpha Particles

Alpha particles They are helium-4 nuclei, He42 Mass: 6.6464835 x 10-27kg Charge: +2e Positively charged, hence deflected by an electric field Deflected by a strong magnetic field Have high ionising power (able to remove electrons from nearby atoms/molecules very effectively), producing a large number of ions(~ 103 to 104) along its path Range of alpha particles in air is about …

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Radioactive Decay

Radioactive decay is the spontaneous disintegration of the nucleus of an atom which results in the emission of particles. Spontaneous Process: Cannot be speed up or slowed down by physical means(changes in pressure or temperature or the decay of other atoms). It is not affected by any chemical condition or the chemical compound that it exists in. Random Process: Radiation …

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