VFA Mixed Practice Test #241

Question 1

p-n junction diode conducts in:

Accepted Answer

Forward bias only — Depletion region shrinks in forward bias. Used as rectifier. Reverse breakdown (Zener) at high reverse voltage.

Answer

Both directions equally

Answer

Reverse bias only

Answer

Never

Question 2

Akshaya — Kerala project:‌​‍

Accepted Answer

e-literacy — e-literacy project.‌​‍

Answer

Transport

Answer

Healthcare

Answer

Fish

Question 3

Intrinsic semiconductors at absolute zero behave like:‌​‍

Accepted Answer

Insulator — No free electrons at 0 K. ‌​‍At higher T, covalent bonds break → some charge carriers. Conductivity rises with T (opposite of metals).

Answer

Metal

Answer

Conductor

Answer

Superconductor

Question 4

A teacher conducts a microteaching session to practice questioning skills. Which feedback focus would be most effective for improving student engagement?

Accepted Answer

A. The teacher's tone and body language during questioning — Effective questioning in microteaching should emphasize the teacher's delivery (tone, body language) as it directly impacts student engagement. While open-ended questions are important, the delivery style is more critical for immediate feedback and improvement.

Answer

B. The number of questions asked

Answer

C. The proportion of open-ended questions used

Answer

D. The time taken to answer each question

Question 5

Calicut University:

Accepted Answer

1968 — 1968.

Answer

1975

Answer

1980

Answer

1985

Question 6

Sodium chloride (NaCl) is a crucial component of intravenous fluids like normal saline. What is its primary physiological role that makes it essential for maintaining fluid balance?

Accepted Answer

B. Maintains osmotic pressure and extracellular fluid volume. — Sodium is the primary cation in the extracellular fluid, and chloride is its main accompanying anion. Together, they are critical for maintaining osmotic pressure, which in turn regulates the distribution of water between intracellular and extracellular compartments, thus maintaining extracellular fluid volume and blood pressure. The other options are not primary physiological roles of NaCl in fluid balance.

Answer

A. Acts as a coenzyme for metabolic reactions.

Answer

C. Directly regulates blood glucose levels.

Answer

D. Functions as a potent antioxidant.

Question 7

Magnetic field inside a long solenoid:‌​‍

Accepted Answer

B = μ₀nI (uniform, along axis) — n = turns per unit length. ‌​‍Outside long solenoid B ≈ 0. Basis for electromagnets.

Answer

Depends on r

Answer

Zero

Answer

Increases outward

Question 8

The law of conservation of energy states that energy:‌​‍

Accepted Answer

Cannot be created or destroyed, only transformed — Total energy of an isolated system is constant — 1st law of thermodynamics.‌​‍

Answer

Can be destroyed

Answer

Disappears in collisions

Answer

Can be created

Question 9

What is the formula for the capacitance of a parallel plate capacitor?‌​‍

Accepted Answer

C = ε₀A/d — With dielectric K: C = Kε₀A/d. Units Farad. Energy stored: ½CV².‌​‍

Answer

C = ε₀d/A

Answer

C = 1/ε₀

Answer

C = A/d

Question 10

Mean kinetic energy per molecule of ideal gas at absolute T is:

Accepted Answer

(3/2)kT — Equipartition: (1/2)kT per DOF. Monatomic gas has 3 translational DOF.

Answer

kT

Answer

(5/2)kT

Answer

RT

VFA Mixed Practice Test #241