DCOA Mixed Practice Test #240

Question 1

Unsustainable sand mining from the riverbeds of Kerala's major rivers poses significant environmental and socio-economic challenges. From an ecological and hydrological perspective, which of the following represents the most critical direct impact of excessive sand extraction on the riverine ecosystem and surrounding areas?

Accepted Answer

B. Lowering of the riverbed and water table, resulting in reduced groundwater recharge, destabilization of riverbanks, and exposure of bridge foundations. — Excessive sand mining directly lowers the riverbed. This lowering causes a corresponding drop in the water table of the surrounding areas, reducing groundwater recharge and affecting wells. It also destabilizes riverbanks, leading to erosion, and exposes the foundations of bridges and other riverine infrastructure, compromising their structural integrity.

Answer

A. Alteration of the river's natural meandering pattern, leading to increased flood risk in upstream regions.

Answer

C. Enhanced deposition of silt and clay downstream, causing blockages in irrigation canals and reduction in reservoir capacities.

Answer

D. Increased salinity intrusion into freshwater aquifers in coastal belts due to a decrease in the overall volume of river water.

Question 2

The unit of force in CGS system is:

Accepted Answer

Dyne — Dyne is the CGS unit of force; 1 N = 10⁵ dynes.

Answer

Newton

Answer

Pascal

Answer

Joule

Question 3

Inert pair effect is seen strongly in:‌​‍

Accepted Answer

Heavier p-block (Tl, Pb, Bi) — Lower oxidation state (by 2) becomes more stable down the group (e.g., Pb²⁺ > Pb⁴⁺; Tl⁺ > Tl³⁺).‌​‍

Answer

Transition metals

Answer

Group 1

Answer

Noble gases

Question 4

In an electrolytic cell, the anode is the:

Accepted Answer

Positive electrode (oxidation) — In electrolytic cells: anode = positive (connected to + terminal); oxidation still occurs there.

Answer

Negative electrode

Answer

Neutral

Answer

Same as cathode

Question 5

The National Human Rights Commission (NHRC) cannot inquire into any matter after the expiry of what period from the date on which the act constituting human rights violation is alleged to have been committed?

Accepted Answer

1 year — NHRC's jurisdiction is limited; it cannot inquire into events older than 1 year from the date of the alleged violation.

Answer

6 months

Answer

2 years

Answer

3 years

Question 6

Ambedkar Jayanti:‌​‍

Accepted Answer

14 Apr — 14 April (B.R. Ambedkar's birthday).‌​‍

Answer

2 Oct

Answer

14 Nov

Answer

5 Sep

Question 7

The largest organ in the human body is:‌​‍

Accepted Answer

Skin — Skin is the largest organ (~1.5-2 sq metres in adults).‌​‍

Answer

Liver

Answer

Heart

Answer

Brain

Question 8

Marayoor in Idukki is famous for:‌​‍

Accepted Answer

Natural sandalwood forests — Marayoor is the only place in Kerala with natural sandalwood forests and is also known for jaggery production.‌​‍

Answer

Coffee plantations

Answer

Teak plantations

Answer

Rubber estates

Question 9

Appam stew:‌​‍

Accepted Answer

Both — Both.‌​‍

Answer

Syrian Christian delicacy

Answer

Breakfast

Answer

Dinner

Question 10

A teacher notices students becoming restless and losing focus during a long lecture. To regain attention and manage the classroom effectively, what immediate strategy should the teacher employ?

Accepted Answer

D. Incorporate a short, interactive activity or a movement break. — When students become restless, incorporating a short, interactive activity or a movement break can effectively re-energize them and refocus their attention. This proactive adjustment prevents further disengagement and helps maintain a positive learning environment without resorting to negative or disruptive interventions.

Answer

A. Continue the lecture, assuming students will eventually refocus.

Answer

B. Assign individual written tasks to quiet them down.

Answer

C. Publicly scold the most restless student to set an example.

DCOA Mixed Practice Test #240