solenoid is .3 m long and is wound with 2 layers of wire. the inner layer consists of 300 turns, the outer alyter of 250 turns. if the current in both layers are 3 A and in the same direction what is the magnetic field at the center of the solonoid?

Explanation:

Magnetic field due to a solenoid

B = μ₀ nI  where n is no of turns per unit length and I is current

for outer  layer of turns

B = μ₀  x (250 / .3) x 3

= 4π x 10⁻⁷ x (250 / .3) x 3

= 3.14 x 10⁻³ T  

for inner layer of turns

B = μ₀  x (300 / .3) x 3

= 4π x 10⁻⁷ x (300 / .3) x 3

= 3.77 x 10⁻³ T

Total magnetic field

= (3.14 + 3.77 ) x 10⁻³ T  

= 6.91 x 10⁻³ T  .

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.

this means that the temperature of both substances will be equal