VFA Mixed Practice Test #750

Question 1

A student observes that when a coin is placed at the bottom of a beaker filled with water, it appears to be raised from its actual position. This phenomenon is primarily due to:

Accepted Answer

C. Refraction of light as it passes from water to air. — The apparent raising of an object submerged in water is a classic example of refraction. Light rays from the coin travel from water (denser medium) to air (rarer medium), bending away from the normal. This bending makes the light appear to originate from a shallower position to the observer's eye. Option A (reflection) causes images but not this specific apparent depth change. Option B (total internal reflection) would prevent light from exiting the water if the angle is too large. Option D (dispersion) is the splitting of light into colors, which is unrelated to the apparent depth phenomenon.

Answer

A. Reflection of light from the water surface.

Answer

B. Total internal reflection within the water.

Answer

D. Dispersion of light by the water molecules.

Question 2

Social Mobility types include:‌​‍

Accepted Answer

Vertical (up/down) and Horizontal (same level different role), Intragenerational and Intergenerational — Classical distinctions in mobility studies — also open vs closed societies, structural vs individual mobility.‌​‍

Answer

Only one type

Answer

Only upward

Answer

Only economic

Question 3

National Anthem duration:‌​‍

Accepted Answer

52 seconds — Full version 52 seconds.‌​‍

Answer

48 seconds

Answer

60 seconds

Answer

55 seconds

Question 4

India became the ___ country to land on the Moon's south pole:‌​‍

Accepted Answer

First — India became the first country to successfully land a spacecraft near the Moon's south polar region.‌​‍

Answer

Fourth

Answer

Second

Answer

Third

Question 5

Aadhaar total enrollment crossed:‌​‍

Accepted Answer

130 crore — Over 130 crore Aadhaar numbers issued as of 2024.‌​‍

Answer

120 crore

Answer

110 crore

Answer

100 crore

Question 6

Kochi Metro inaugurated:‌​‍

Accepted Answer

2017 — 17 June 2017 by PM Modi.‌​‍

Answer

2018

Answer

2016

Answer

2019

Question 7

RMS speed of ideal gas molecules at T:

Accepted Answer

√(3RT/M) — v_rms = √(3RT/M) = √(3kT/m). Mean = √(8RT/πM); most probable = √(2RT/M).

Answer

√(RT/M)

Answer

√(2RT/M)

Answer

√(RT)

Question 8

Seven wonders of world (new list 2007):‌​‍

Accepted Answer

Taj Mahal is one — Taj Mahal included.‌​‍

Answer

Only historical

Answer

All excluded India

Answer

Only architectural

Question 9

Maximum range of projectile for fixed initial speed occurs at angle:‌​‍

Accepted Answer

45° — R = u² sin(2θ)/g is maximum when sin(2θ)=1 i.e. ‌​‍θ=45° (neglecting air resistance).

Answer

30°

Answer

90°

Answer

60°

Question 10

The Contact process manufactures:‌​‍

Accepted Answer

H₂SO₄ — Contact: S → SO₂ → SO₃ (V₂O₅ catalyst) → oleum → H₂SO₄.‌​‍

Answer

NH₃

Answer

HCl

Answer

HNO₃

VFA Mixed Practice Test #750