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A proton is about 1840 times heavier than an electron. When it is accelerated by a potential difference of 1 kV, its kinetic energy will be

• 1840 keV

• 1/1840 keV

• 1 keV

• 920 keV

A radioactive substance decays to 1/16^th of its initial activity in 40 days. The half-life of the radioactive substance expressed in days is

• 2.5

• 5

• 10

• 20

A neutron makes a head-on elastic collision with a stationary deuteron. The fractional energy loss of the neutron in the collision is

• 16/81

• 8/9

• 8/27

• 2/3

Nuclear fusion is possible

• only between light nuclei

• only between heavy nuclei

• between both light and heavy nuclei

• only between nuclei which are stable against β-decay

Radioactive nuclei that are injected into a patient collect at certain sites within its body, undergoing radioactive decay and emitting electromagnetic radiation. These radiations can then be recorded by a detector. This procedure provides an important diagnostic tool called

• gamma camera

• CAT scan

• radiotracer technique

• gamma ray spectrosccopy

In a material medium, when a positron meets an electron both the particles annihilate leading to the emission of two gamma ray photons. This process forms the basis of an important diagnostic procedure called 

• MRI

• PET

• CAT

• SPECT

Assertion: Radioactive nuclei emit  β^- particles.

Reason: Electrons exist inside the nucleus.

• if both assertion and reason are true and the reason is the correct explanation of the assertion

• if both assertion and reason are true and the reason is not the correct explanation of the assertion

• if assertion is true but reason is false

• If both assertion and reason are false statements

Assertion: Neutrons penetrate matter more readily as compared to protons.

Reason: Neutrons are slightly more massive than protons.

• if both assertion and reason are true and the reason is the correct explanation of the assertion

• if both assertion and reason are true and the reason is not the correct explanation of assertion

• if assertion is true but reason is false

• if both assertion and reason are false statements

Assertion:  Quasar emits radiowaves more than radio galaxy. 

Reason:  Quasar has very small size

• If both the assertion and reason are true and reason is a correct explanation of the assertion.

• If both assertion and reason are true but assertion is not a correct explanation of the assertion.

• If the assertion is true but the reason is false.

• If both assertion and reason are false.

Mass of the proton is 1840 times that of electron. It is accelerated through a potential difference of 1V. Find its kinetic energy.

• 6 eV

• 2 eV

• 10 eV

• 1 eV