GATE Life Cycle Assessment: practice questions

1 · Goal and scope: functional unit, system boundary, cut-off · medium

Which of the following is NOT one of the items ISO 14044 requires the goal of an LCA to state?

1. The intended application of the study
2. The intended audience to whom results will be communicated
3. Whether results are to be used in comparative assertions disclosed to the public
4. The impact assessment method and software to be used

2 · Goal and scope: functional unit, system boundary, cut-off · medium

ISO 14044 lists three bases for cut-off criteria for deciding which inputs to include. Which set is correct?

1. Mass, energy and environmental significance
2. Mass, cost and number of suppliers
3. Energy, distance transported and shelf life
4. Cost, data availability and reporting convenience

3 · Life cycle inventory: foreground and background data · hard

In the matrix formulation of LCA, how is the scaling vector s that delivers the final demand f obtained?

1. By multiplying the intervention matrix B by the final demand f directly, s = B·f
2. By solving A·s = f, that is s = A⁻¹·f, where A is the technology matrix
3. By multiplying the characterisation matrix Q by the inventory vector, s = Q·g
4. By adding the columns of the technology matrix A and dividing by the demand f

4 · Allocation and system expansion for multifunctional processes · easy

According to ISO 14044, what is the first-preferred way to handle a multifunctional process?

1. Allocate burdens in proportion to the economic value of the co-products
2. Allocate burdens in proportion to the mass of each co-product
3. Avoid allocation by subdividing the process or by expanding the system
4. Assign all burdens to the co-product with the largest output

5 · Allocation and system expansion for multifunctional processes · medium

Crushing soybeans yields 0.79 kg meal (price 0.40 per kg) and 0.19 kg oil (price 1.00 per kg) per kg of beans. What share of the crushing burden goes to the oil under economic allocation?

1. 19.4 %
2. 62.5 %
3. 37.5 %
4. 71.4 %

6 · Climate change, eutrophication, acidification, water and land-use categories · medium

A farm emits 20 kg NH3 and 5 kg NOx (as NO2). Using acidification factors of 1.88 kg SO2-eq/kg for NH3 and 0.70 for NO2, what is the acidification result?

1. 25.0 kg SO2-eq
2. 41.1 kg SO2-eq
3. 37.6 kg SO2-eq
4. 17.8 kg SO2-eq

7 · Climate change, eutrophication, acidification, water and land-use categories · medium

In water footprinting within LCA, impact assessment of water scarcity is based on which inventory quantity?

1. Water withdrawal, the total volume taken from the source
2. Water consumption, the water not returned to the same catchment
3. Grey water, the volume needed to dilute pollutants to standards
4. Green water, the rainfall stored in the soil and used by crops

8 · Climate change, eutrophication, acidification, water and land-use categories · easy

A crop yields 4.0 t/ha in one year. What is its land occupation per kilogram?

1. 0.25 m²·yr per kg
2. 2.5 m²·yr per kg
3. 25 m²·yr per kg
4. 4.0 m²·yr per kg

9 · Biogenic carbon and land-use change in LCA · easy

Under the '−1/+1' approach to biogenic carbon, how are uptake and release of biogenic CO2 characterised?

1. Uptake and release are both counted as zero, assuming they balance
2. Uptake is counted as +1 and release as −1 kg CO2-eq per kg CO2
3. Uptake −1, release +1 kg CO2-eq per kg CO2
4. Only uptake is counted, and release of biogenic CO2 is ignored

10 · Environmental product declarations and critical review · medium

Which LCA study does ISO 14044 require to undergo critical review by a panel of interested parties?

1. A study supporting a comparative assertion disclosed to the public
2. A screening study used only by the company's own design team
3. A study of a single product communicated to one business customer
4. A cradle-to-gate inventory used to update a background database