Physics Test - 4

Directions: The following question has four choices out of which ONLY ONE is correct.

An open knife edge of mass M is dropped from a height 'h' on a wooden floor. If the blade penetrates 's' into the wood, the average resistance offered by the wood to the blade is

A stone is dropped from a certain height. After falling for 5 sec, the stone breaks through a pane of glass and instantaneously, loses half of its velocity. If the stone takes one more second to reach the ground, what is the height of the glass above the ground? (Given g = 10 m/s²)

We wish to see inside an atom. Assume the atom to have a diameter of 100 pm. This means that one must be able to resolve a width of say 10 pm. If an electron microscope is used, the energy required should be

The half-life of ¹³¹I is 8 days. If we have a sample of ¹³¹I at time t = 0, we can assert that

A radioactive nuclide can decay simultaneously by two different processes, which have individual decay constantsλ₁ anaλ₂ . The effective decay constant of the nuclide (λ) is given by

The binding energies for nuclei ₁H¹, ₂He⁴, ₂₆Fe⁵⁶ and ₉₂U²³⁵ are 2.22, 28.3, 492 and 17.86 MeV, respectively. The most stable nucleus is

The binding energy per nucleon of ₁H² is 1.1 MeV and binding energy per nucleon of ₂He⁴ is 7 MeV. The energy released when two ₁H² combine to form ₂He⁴ is

For a certain radioactive substance, it is observed that after 4 hours, only 6.25% of the original sample is left undecayed. Which of the following statements is incorrect?

Li nucleus has three protons and four neutrons. Mass of lithium nucleus is 7.016005 amu. Mass of proton is 1.007277 amu and mass of neutron is 1.008665 amu. Mass defect for lithium nucleus in amu is

During the adiabatic expansion of 2 moles of a gas, the internal energy was found to have decreased by 100 J. The work done by the gas in this process is