250+ TOP MCQs on Characteristic Loads and Answers

Design of Steel Structures Multiple Choice Questions on “Characteristic Loads”.

1. Which IS code is used for calculating different loads on different structures?
a) IS 800
b) IS 200
c) IS 300
d) IS 875
Answer: d
Clarification: IS 875 (all 5 parts) is recommended by Bureau of Indian Standards for calculating various types of loads on the structure. Part 1 is for dead loads, part 2 for imposed loads, part 3 for wind load, part 4 for snow loads and part 5 for special loads and combinations.

2. Which of the following load is to be considered on liquid retaining structure?
a) hydrostatic load
b) wave and current load
c) earth pressure
d) dynamic load
Answer: a
Clarification: Hydrostatic load is considered on liquid retaining structures or hydraulic structures. Wave and current load is considered in marine and offshore structure. Earth pressure is considered in basements, retaining walls, column footings, etc. Dynamic load is due to earthquake and wind.

3. What is P-Δ effect?
a) earthquake load
b) second order moments arising from joint displaced
c) second order moments arising from member deflection
d) load due to shrinkage effect
Answer: b
Clarification: Second order moments arising from joint displaced is called P-Δ effect and second order moments arising from member deflection is called P-δ effect.

4. Match the pair :

	(A) Mass and gravitational effect		(i) wind load
	(B) Mass and acceleration effect 		(ii) load due to settlement
	(C) Environmental effects			(iii) imposed load

a) A-i, B-ii, C-iii
b) A-iii, B-ii, C-i
c) A-iii, B-i, C-ii
d) A-ii, B-iii, C-i
Answer: c
Clarification: Load on structure may be due to following :
1) Mass and gravitational effect : examples of such loads are dead loads, imposed loads, snow and ice loads, earth loads, etc.
2) Mass and acceleration effect : examples of such loads are those caused by earthquake, wind, impact, blasts, etc.
3) Environmental effects : examples of such loads are due to temperature difference, settlement, shrinkage, etc.

5. The probability that a specific load will be exceeded during life of structure depends on _______
a) wind
b) factor of safety
c) partial factor of safety
d) period of exposure
Answer: d
Clarification: The probability that a specific load will be exceeded during life of structure depends on period of exposure. It also depends on magnitude of design load.

6. What is characteristic load?
a) seismic load
b) load which will be exceeded by certain probability during life of structure
c) load which will not be exceeded by certain probability during life of structure
d) pressure load
Answer: c
Clarification: Characteristic load is the load which will not be exceeded by certain assumed or pre-assumed probability during life of structure. These loads are anticipated loads due to self weight, imposed load, snow, wind load, etc.

7. Which of the following is not included in imposed load classification?
a) Residential load
b) Earthquake load
c) Industrial load
d) Educational load
Answer: b
Clarification: Imposed loads are gravity loads other than dead load and cover factors such as occupancy by people, stored material etc. It is classified into following groups : (i)residential, (ii)educational, (iii)institutional, (iv)assembly halls, (v)office and business buildings, (vi)mercantile buildings, (vii)industrial, (viii)storage buildings.

8. What is the minimum imposed load on roof trusses as per IS code?
a) 0.5 kN/m²
b) 0.4 kN/m²
c) 0.9 kN/m²
d) 0.75 kN/m²
Answer: b
Clarification: As per IS 875, the minimum imposed load on roof truss should be 0.4 kN/m². For sloping roof upto 10˚, the imposed load is taken as 0.5 kN/m² if access is not provided and 0.75 kN/m² if access is provided.

9. For roofs of slope greater than 10˚, the imposed load is reduced by ____ for every degree rise in slope.
a) 0.02 kN/m²
b) 0.05 kN/m²
c) 0.75 kN/m²
d) 0.5 kN/m²
Answer: a
Clarification: As per IS 875, for roofs of slope greater than 10^o, the imposed load is taken as 0.75 kN/m² and reduced by 0.02 kN/m² for every degree rise in slope.

10. Calculate imposed load on roof truss of span 20m with slope of 20^o.
a) 0.75 kN/m²
b) 0.95 kN/m²
c) 0.45 kN/m²
d) 0.55 kN/m²
Answer: d
Clarification: As per IS 875, for roofs of slope greater than 10^o, the imposed load is reduced by 0.02 kN/m² for every degree rise in slope.
Therefore, Imposed load = 0.75 – 0.02*(20^o-10^o) = 0.55 kN/m².