Question # 1

When light of particular frequency is allowed to fall upon a metal surface electrons are emitted from a these emitted electrons are called.

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Photons

Holes

Quants

Photo electrons

Work function is generally expressed in.

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Electron volt

Joules

Newtons

Gauss

Alpha particles are used for the treatment of skin of a patient due to.

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Highly ionizing power

Low penetration power

Positively charged particles

Helium nucler

The energy in electron volts necessary to remove the most loosely bound electron from the neutral atom is known as.

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Faraday energy

Wave number

Ionization Potential

Excitation potential

Which one of the following gates in a a universal gate.

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OR

AND

NOT

NAND

An operational amplifier have how many input terminals.

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One

Two

Three

Four

The wavelength of Lyman series for hydrogen spectrum lies in the.

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Visible region

Ultraviolet region

Infrared region

Far infrared region

How positives feedback will effect an amplifier.

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Increases the voltage gain

Decreases the voltage gain

Imitates oscillation to occur

Damaged it

The half life of a radioactive substance as compared to its mean lif eis.

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30%

50%

70%

90%

The angular speed of an electron in the nth orbit of Bohr's hydrogen atom is.

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Directly proportional to n

Directly proportional to n2

Inversely proportional to n

Inversely proportional to n2

Transistor are made from

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Plastics

Metals

Insulators

Doped semiconductors

The most abundant isotope of neon is.

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Neon -20

Neon -21

Neon -22

Both a and c

When we pass a radiation from a radioactive material through an electric field.

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All three kinds of rays will be deflected

Only the Gama rays are deflected

The Alpha and Beta particles are deflected

Only the alpha particles are deflected

At high temperature a body generally emits redactions of.

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Small wavelengths

Long wavelengths

Moderates wavelengths

Zero wavelengths

The force that bonds protons and neutrons together int he nucleus despite the electrical repulsion of the protons is called.

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Molecular force

Nuclear force

Atomic force

Gravitational force

Mosley's law establishes the x rays fluorescence's of target element with its.

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Atomic weight

Atomic number

Density

Lattice constant

The most suitable material for moderator in a nuclear reactor is.

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B

Cd

D2O

Uranium

Negative feedback

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Increases stability

Decreases stability

Produces oscillatory

Cannot occur

The half life of radium -226 is

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1620 years

45 x 10⁹ years

3.8 days

23.5 minutes

Which of the following is not a mode of radioactive decay

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Nuclear fusion

Alpha decay

Electron capture

Positron emission

The neutral atoms of all isotopes of the same element contain the same numbers of.

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Electrons and protons

Electrons and neutrons

Neutrons

Neutrons and protons

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