Slope and Deflection

JKSSB Junior Engineer (Civil) · Mechanics and Structural Analysis · 9 practice questions with answers and explanations: 6 Easy, 1 Medium, 2 Hard.

Sample questions

Sample Easy question 1

The deflection of a beam is inversely proportional to its:

  1. Flexural rigidity EI
  2. Span
  3. Load
  4. Weight only
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Answer: A. A larger E or I gives a smaller deflection.

Sample Easy question 2

If the depth of a rectangular beam is doubled with the same width, the deflection under a given load becomes:

  1. One-sixteenth
  2. Half
  3. One-eighth
  4. One-quarter
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Answer: C. I is proportional to d³, so doubling d multiplies I by 8.

Sample Easy question 3

Macaulay's method is used to find the deflection of beams:

  1. Carrying several loads or discontinuous loading
  2. Of very large span only
  3. Made of concrete only
  4. That are statically determinate only
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Answer: A. A single equation for the bending moment is integrated through the whole span.

Sample Medium question 4

A simply supported beam of 5 m span carries a central load of 24 kN, with EI = 15,625 kN·m². The central deflection is:

  1. 8 mm
  2. 2 mm
  3. 0 mm
  4. 4 mm
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Answer: D. δ = WL³ ÷ 48EI = 24 × 125 ÷ (48 × 15,625) = 0.004 m.

Sample Hard question 5

A simply supported beam of 5 m span with a central load of 24 kN and EI = 15,625 kN·m² has a slope at the support (WL² ÷ 16EI) of:

  1. 0.004 rad
  2. 0.0048 rad
  3. 0.0012 rad
  4. 0.0024 rad
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Answer: D. θ = 24 × 25 ÷ (16 × 15,625) = 0.0024 rad.

Sample Hard question 6

A cantilever of 2 m carries a UDL of 10 kN/m over its full length, with EI = 5,000 kN·m². The tip deflection (wL⁴ ÷ 8EI) is:

  1. 2 mm
  2. 8 mm
  3. 32 mm
  4. 4 mm
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Answer: D. δ = 10 × 2⁴ ÷ (8 × 5,000) = 0.004 m = 4 mm.

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