NEET General 5

Question 1

Which law of thermodynamics states that the total entropy of an isolated system always increases?

Accepted Answer

Second Law

Answer

The Second Law of Thermodynamics states that entropy of an isolated system never decreases and natural processes are irreversible.

Question 2

What is the role of ribosomes in a cell?

Accepted Answer

Protein synthesis

Answer

Ribosomes are the sites of protein synthesis (translation), reading mRNA codons to assemble amino acid chains.

Question 3

Which quantum number describes the shape of an atomic orbital?

Accepted Answer

Azimuthal quantum number (l)

Answer

The azimuthal (angular momentum) quantum number l determines the shape of the orbital: l=0 (s), l=1 (p), l=2 (d).

Question 4

A wave has frequency 500 Hz and wavelength 0.68 m. What is its speed?

Accepted Answer

340 m/s

Answer

Wave speed v = fλ = 500 × 0.68 = 340 m/s, which is approximately the speed of sound in air.

Question 5

Which hormone is secreted by the adrenal medulla in response to stress?

Accepted Answer

Adrenaline (Epinephrine)

Answer

The adrenal medulla secretes adrenaline (epinephrine) and noradrenaline, preparing the body for a 'fight or flight' response.

NEET - National Eligibility cum Entrance Test Practice Test