NEET General 5 β Questions and Answers
Question 1: Which law of thermodynamics states that the total entropy of an isolated system always increases?
- Zeroth Law
- First Law
- Second Law (Correct answer)
- Third Law
Correct answer: Second Law
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?
- DNA replication
- Protein synthesis (Correct answer)
- Energy production
- Lipid metabolism
Correct answer: Protein synthesis
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?
- Principal quantum number (n)
- Azimuthal quantum number (l) (Correct answer)
- Magnetic quantum number (mβ)
- Spin quantum number (mβ)
Correct answer: Azimuthal quantum number (l)
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?
- 680 m/s
- 340 m/s (Correct answer)
- 1000 m/s
- 0.00136 m/s
Correct answer: 340 m/s
Wave speed v = fΞ» = 500 Γ 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?
- Cortisol
- Aldosterone
- Adrenaline (Epinephrine) (Correct answer)
- Insulin
Correct answer: Adrenaline (Epinephrine)
The adrenal medulla secretes adrenaline (epinephrine) and noradrenaline, preparing the body for a 'fight or flight' response.
Question 6: What is the general formula for alkanes?
- CβHββ
- CβHββββ
- CβHββββ (Correct answer)
- CβHββββ
Correct answer: CβHββββ
Alkanes are saturated hydrocarbons with only single bonds, following the general formula CβHββββ.
Question 7: Which plant tissue is responsible for the transport of water and minerals from roots to leaves?
- Phloem
- Xylem (Correct answer)
- Cambium
- Epidermis
Correct answer: Xylem
Xylem conducts water and dissolved minerals upward from roots to aerial parts through dead, hollow tracheary elements.
NEET General 5
Which law of thermodynamics states that the total entropy of an isolated system always increases?