Question # 1

The usefulness of X rays is largely due to their

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Mass

Density

Volume

Penetrating power

The half life of isotopes X is four days and its initial mass is 32 mg What mass of the isotope X will remain after twelve days.

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2 mg

4 mg

8 mg

18 mg

Nuclear force as compared to electrostatic force is.

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Weaker and long range

Weaker and short range

Stronger and longer range

Stronger and short range

What is the overall gain, if three amplifiers each with a gain of 30 are cacaded.

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30

90

270

27,000

Choose the one which acts as single inverter.

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Common emitter

common collector

Common base

Diode

The mass defect of Bohr's atomic model is

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Exclusion of nuclear motion

missing of classical and quantum theories

Failed to explain the fine structure of spectral line

All of the above

What is the quantitative description of the effect of radiation on the living tissue.

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Radiation dosimetry

Radioactive dating

Telemetry

Dosage

The most readily fissionable isotope of uranium has atomic mass of

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234

235

236

238

Which of the following circuits is used as local oscillator in radio receivers.

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AF oscillator

Phase Local Loop

RF oscillator

All of the above

Atomic reactor is based on

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Controlled chain reaction

Uncontrolledly chain reaction

Nuclear fission

Nuclear fusion

Specially designed solid state detector can be used to detect.

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Alpha particles

Beta particles

Gama rays

X- rays

A gama ray of energy 1900 MeV is absorbed by

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Proton antiproton pair

Electron positron pair

Producing heat in the substance

The orbit

Which quantity remains fixed in isobars.

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Mass number

Atomic number

Number of neutrons

Number of protons

The decay process in which an unstable nucleus splits into two fragments of comparable mass is known as.

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Nuclear fission

nuclear fusion

Radioactivity

Carbon dating

One rem is equal to.

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0.1 Sv

0.01 Sv

0.001 Sv

0.0001 SV

The minimum amount of energy in an individual electron has to gain to escape from a particular surface is called.

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Threshold frequency

work function

Wave number

Kinetic energy

the alpha particle does not travel for enough in air.

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Due to its intense ionization

Due to its large mass

Due to its high charge

Due to its Hight Ionization

Radioactive substances do not emit

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Alpha particles

Beta particles

Gama rays

Neutrons

In Compton's effect the change in wavelength of a scattered photon is called.

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Angle of emergence

Angle of refraction

Angle of deviation

Compton shift

The process of pair production will take place if the energy of photon is greater than

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0.21 MeV

0.51 MeV

1.51 MeV

1.21 MeV

Two electrons approach each other their relative velocity will be.

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Zero

c

c/2

Infinity

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