Light is incident on the left face of an isosceles prism; with an apex angle of 49o, such that the light exiting the right face is parallel to its surface.
what is the index of refraction of the prism, if the angle of incidence on the left face side is 19o to the normal of the face? light is incident towards the apex.

Explanation:

By Snell's law we know at the left surface

now we have

now on the other surface we know that

angle of incidence =

so again we have

so we have

also we know that

By solving above equation we have

explanation:

newton's third law, for every action there is an equal and opposite reaction.

answer: the correct answer is 1.

explanation: there are various process in which a radioactive nuclei decays:

1) alpha decay: in this process, a heavier nuclei decays into lighter nuclei by releasing alpha particle. the mass number is reduced by 4 units.

2) electron capture: in this decay process, a parent nuclei absorbs an electron and gets converted into a neutron. simply, a proton and an electron combines together to form a neutron. mass number does not change in this process.

3) gamma ray emission: it is a decay process in which an unstable nuclei gives excess energy by a spontaneous electromagnetic process. this decay releases . this process does not change the mass number.

4) positron emission: it is a type of decay process, in which a proton gets converted to neutron and an electron neutrino. this is also known as -decay. in this the mass number remains same.

from the above information, we see that only alpha-decay is producing a change in the mass number of the nucleus.