Second Year Physics Chapter 19 Online MCQ Test for 2nd Year Physics Chapter 19 Dawn of Modern Physics Preparation

When the K.E. of photoelectric is zero, the frequency of incident photon is.

• Less than A
• greater than B
• Equal to C
• Much greater D

The number of electrons emitted depends upon

• Colour of target surface A
• Shape of surface B
• Frequency of incident light C
• Intensity of incident light D

Max planck received noble prize in:

• 1927 A
• 1932 B
• 1918 C
• 1914 D

Internal frame is a frame is which

• 1st law holds A
• 2nd law holds B
• 3rd law holds C
• Kelvin's law holds D

Antiparticle of electron is.

• proton A
• Photon B
• Positron C
• Neutron D

Platinum wire becomes yellow at a temperature of.

• 900 ^oC A
• 1300^oC B
• 1600^oC C
• 500^oC D

When platinum wire is heated, it changes to cherry red at temperature.

• 500^oC A
• 900^oC B
• 1100^oC C
• 1300^oC D

Which one of the following physical quantities change with relativistic speed?

• Length A
• Time B
• Mass C
• All of above D

If an object moves with speed of light, its mass will be.

• Zero A
• Maximum B
• Minimum C
• infinity D

The Compton effect is associated with

• X-rays A
• y-rays B
• Positive rays C
• ß-rays D

Maximum Compton shift is observed at.

• 30^oC A
• 90^oC B
• 45^oC C
• 180^oC D

If the energy of photon is 10 eV and work function is 5 eV, then the a value of stopping potential will be

• 50 V A
• 2 V B
• 5 V C
• 15 V D

In an nihilation emitted photons moves in opposite directions to conserve.

• Mass A
• Charge B
• Energy C
• Momentum D

Which is the most refined form of matter.

• Smoke A
• Fog B
• Light C
• Electron D

The position has charge which is in magnitude equal to the charge on

• Electron A
• Proton B
• β particle C
• All D

• Wien's constant A
• Planck's constant B
• Davison constant C
• Lumber's constant D

An electron miroscope emplys which to one of the following particles?

• Electron ahve a wave nature A
• Electrons can be focused by an electric field B
• Electrons can be focused by a magnetic field C
• All of the above D