CELPHY -2k23

Force acting on a particle moving with constant speed in a friction less medium is__

• Always zero

• Need not be zero

• Always non zero.

• Cannot be concluded

Dimensionless constants are__

• Length

• Plancks constant

• Boltzmann Constant

• π,e

At what electric field intensity, the insulating properties of air break down?

• 7×10⁶ V/cm

• 7×10⁶V/m

• 3×10⁶V/m

• 3×10⁶V/cm

Formula for Young's modulus is Y=(Stress)/(strain).

If the applied stress is double then the new value of Young's modulus is,

• Halved

• Doubled

• Undetermined

• Unchanged

A particular material of length L and area A had resistance R .

Is melted and reformed so as the length is halved. Now, the new value of the resistance is

• 2R

• ½R

• ¼R

• No change

The half lifetime of a radioactive material is 5 years. In 10 years the amount of substance disintegrated is __

• 25% of initial amount

• 75% of initial amount

• 12.5% of initial amount

• Cannot determine

According to Maxwell boltzmann statistics the probability of finding any particle as the energy increases at a given temperature,

• Increases 1/e Times.

• Increases

• Decreases

• Greater than 1

Who discovered the neutron?

• Ernest Rutherford

• J J Thomson

• James Chadwick

• John Dalton

The derivative of function y=x³/3 is plotted against x-axis the resulting graph is in the shape of______

The value of 1³+2³+3³+4³+5³ is_______.