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Question 671

RRB JE 2026• Technical Abilities

In the parallelogram method of vector addition, two vectors are drawn from the same point as adjacent sides of a parallelogram. What does the diagonal passing through the common point represent?

  1. AOption (a)

    The difference between the two vectors

  2. BOption (b)

    The resultant vector in both magnitude and direction

  3. COption (c)

    The average of the two vectors

  4. DOption (d)

    The scalar sum of the two vectors

View answer & explanation

Correct answer

Answer: (a)A.

The difference between the two vectors

Explanation not yet available.

Question 672

RRB JE 2026• Technical Abilities

Why does high-density polythene exhibit greater tensile strength than low-density polythene?

  1. AOption (a)

    High-density polythene is manufactured at higher temperatures

  2. BOption (b)

    Low-density polythene contains more amorphous chain regions

  3. COption (c)

    Low-density polythene contains extensive cross-linked structures

  4. DOption (d)

    High-density polythene contains linear and closely packed chains

View answer & explanation

Correct answer

Answer: (a)A.

High-density polythene is manufactured at higher temperatures

Explanation not yet available.

Question 673

RRB JE 2026• Technical Abilities

Which of the following equations is dimensionally consistent?

  1. AOption (a)

    Energy = mass × velocity

  2. BOption (b)

    Force = mass × acceleration

  3. COption (c)

    Power = force × time

  4. DOption (d)

    Velocity = mass × time

View answer & explanation

Correct answer

Answer: (a)A.

Energy = mass × velocity

Explanation not yet available.

Question 674

RRB JE 2026• Technical Abilities

What does the Aufbau principle state about electron filling in orbitals?

  1. AOption (a)

    Energy levels do not affect electron filling order

  2. BOption (b)

    Lower energy orbitals filled before higher energy orbitals

  3. COption (c)

    Orbitals filled randomly without energy consideration

  4. DOption (d)

    Higher energy orbitals filled before lower energy orbitals

View answer & explanation

Correct answer

Answer: (a)A.

Energy levels do not affect electron filling order

Explanation not yet available.

Question 675

RRB JE 2026• Technical Abilities

A vehicle manufacturer is designing engines compatible with both petrol and alcohol-based fuels. What challenge must be addressed to ensure efficient engine performance with alcohol blends?

  1. AOption (a)

    Alcohol remains completely immiscible with petroleum-based fuels

  2. BOption (b)

    Alcohol shows complete resistance to combustion inside engines

  3. COption (c)

    Alcohol tends to absorb water and corrode metallic engine parts

  4. DOption (d)

    Alcohol tends to freeze easily under normal room conditions

View answer & explanation

Correct answer

Answer: (a)A.

Alcohol remains completely immiscible with petroleum-based fuels

Explanation not yet available.

Question 676

RRB JE 2026• Technical Abilities

A community water supply contains fluoride at 3 ppm. Which health effect is most likely to appear first among long-term consumers of this water?

  1. AOption (a)

    Severe skeletal deformities due to chronic fluoride exposure

  2. BOption (b)

    Loss of tooth enamel due to complete fluoride absence

  3. COption (c)

    Increased tooth decay due to inadequate fluoride exposure

  4. DOption (d)

    Brown mottling of teeth due to excess fluoride exposure

View answer & explanation

Correct answer

Answer: (a)A.

Severe skeletal deformities due to chronic fluoride exposure

Explanation not yet available.

Question 677

RRB JE 2026• Technical Abilities

Which molecule contains a central atom that has an incomplete octet in its Lewis structure and completes the octet by accepting a lone pair through coordinate bonding?

  1. AOption (a)

    In the formation of the hydronium ion from water

  2. BOption (b)

    In the formation of the tetrafluoroborate ion from Boron trifluoride

  3. COption (c)

    In the formation of carbonate ion from carbon dioxide

  4. DOption (d)

    In the formation of the ammonium ion from ammonia

View answer & explanation

Correct answer

Answer: (a)A.

In the formation of the hydronium ion from water

Explanation not yet available.

Question 678

RRB JE 2026• Technical Abilities

Which statement best defines electron gain enthalpy for an isolated gaseous atom?

  1. AOption (a)

    Energy released when atoms combine to form stable molecules

  2. BOption (b)

    Energy required to break bonds present in chemical compounds

  3. COption (c)

    Energy required to remove electron from isolated gaseous atom completely

  4. DOption (d)

    Energy released or absorbed when isolated gaseous atom gains electron

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Correct answer

Answer: (a)A.

Energy released when atoms combine to form stable molecules

Explanation not yet available.

Question 679

RRB JE 2026• Technical Abilities

In the formation of sp hybrid orbitals, what is the geometry adopted by a molecule such as BeCl2?

  1. AOption (a)

    Octahedral

  2. BOption (b)

    Trigonal planar

  3. COption (c)

    Tetrahedral

  4. DOption (d)

    Linear

View answer & explanation

Correct answer

Answer: (a)A.

Octahedral

Explanation not yet available.

Question 680

RRB JE 2026• Technical Abilities

Which process uses oil and water to separate valuable minerals from impurities during ore concentration?

  1. AOption (a)

    Magnetic separation method

  2. BOption (b)

    Leaching process

  3. COption (c)

    Froth flotation method

  4. DOption (d)

    Electrolytic refining method

View answer & explanation

Correct answer

Answer: (a)A.

Magnetic separation method

Explanation not yet available.
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