33 real Renewable & Storage Design questions from the Electrical Design bank, as asked in Indian campus drives and tech interviews. Every question has a verified answer and an AI-tutor explanation on placd — free to start.
1. What is IEC 61215 and IEC 61730?
Junior
A.grid-code requirements that wind and solar plants ride through low and high voltage, provide reactive support and respond to frequency
B.module design-qualification tests (thermal cycling, humidity-freeze, mechanical load) and module safety standard; ALMM listing is also mandatory for government projects
C.inverter algorithm such as perturb-and-observe or incremental conductance that tracks the knee of the I-V curve where power peaks as irradiance changes
D.Type 1 fixed-speed induction, Type 2 variable-slip wound rotor, Type 3 DFIG with about 30% partial converter, Type 4 full-converter synchronous
2. Which term means: "module design-qualification tests (thermal cycling, humidity-freeze, mechanical load) and module safety standard; ALMM listing is also mandatory for government projects"?
A.IEC 61215 and IEC 61730 — module design-qualification tests (thermal cycling, humidity-freeze, mechanical load) and module safety standard; ALMM listing is also mandatory for government projects
B.IEC 61215 and IEC 61730 — module power falls about 0.3–0.4% per °C above the 25 °C STC cell temperature, so a 60 °C cell loses 12–14% output
C.IEC 61215 and IEC 61730 — inverter loading ratio of 1.2–1.4 oversizes the array to lift capacity utilisation, accepting clipping at peak irradiance
D.IEC 61215 and IEC 61730 — string units up to a few hundred kW give granular MPPT and easy replacement; central 1–5 MW units give lower cost per watt for uniform utility arrays
A.module power falls about 0.3–0.4% per °C above the 25 °C STC cell temperature, so a 60 °C cell loses 12–14% output
B.module design-qualification tests (thermal cycling, humidity-freeze, mechanical load) and module safety standard; ALMM listing is also mandatory for government projects
C.GHI is total on a horizontal plane, DNI the direct beam and DHI the diffuse part; most of India receives 4–7 kWh/m² per day
D.inverter algorithm such as perturb-and-observe or incremental conductance that tracks the knee of the I-V curve where power peaks as irradiance changes
5. Which term means: "inverter algorithm such as perturb-and-observe or incremental conductance that tracks the knee of the I-V curve where power peaks as irradiance changes"?
A.MPPT — inverter loading ratio of 1.2–1.4 oversizes the array to lift capacity utilisation, accepting clipping at peak irradiance
B.MPPT — Type 1 fixed-speed induction, Type 2 variable-slip wound rotor, Type 3 DFIG with about 30% partial converter, Type 4 full-converter synchronous
C.MPPT — inverter algorithm such as perturb-and-observe or incremental conductance that tracks the knee of the I-V curve where power peaks as irradiance changes
D.MPPT — GHI is total on a horizontal plane, DNI the direct beam and DHI the diffuse part; most of India receives 4–7 kWh/m² per day
A.Irradiance terms — Type 1 fixed-speed induction, Type 2 variable-slip wound rotor, Type 3 DFIG with about 30% partial converter, Type 4 full-converter synchronous
B.Irradiance terms — module power falls about 0.3–0.4% per °C above the 25 °C STC cell temperature, so a 60 °C cell loses 12–14% output
C.Irradiance terms — inverter loading ratio of 1.2–1.4 oversizes the array to lift capacity utilisation, accepting clipping at peak irradiance
D.Irradiance terms — GHI is total on a horizontal plane, DNI the direct beam and DHI the diffuse part; most of India receives 4–7 kWh/m² per day
11. Which term means: "modules in series chosen so Voc at the coldest site temperature stays below the 1000/1500 V limit and Vmp at the hottest stays above MPPT minimum"?
A.String sizing — grid-code requirements that wind and solar plants ride through low and high voltage, provide reactive support and respond to frequency
B.String sizing — modules in series chosen so Voc at the coldest site temperature stays below the 1000/1500 V limit and Vmp at the hottest stays above MPPT minimum
C.String sizing — module power falls about 0.3–0.4% per °C above the 25 °C STC cell temperature, so a 60 °C cell loses 12–14% output
D.String sizing — module design-qualification tests (thermal cycling, humidity-freeze, mechanical load) and module safety standard; ALMM listing is also mandatory for government projects
A.string units up to a few hundred kW give granular MPPT and easy replacement; central 1–5 MW units give lower cost per watt for uniform utility arrays
B.GHI is total on a horizontal plane, DNI the direct beam and DHI the diffuse part; most of India receives 4–7 kWh/m² per day
C.energy equals load times duration over depth of discharge and round-trip efficiency; LFP cells allow 80–90% DoD over 4000-plus cycles
D.Type 2 DC SPDs at array and inverter plus equipotential bonding of module frames per IEC 62305-3 and IEC 61643
14. Which term means: "string units up to a few hundred kW give granular MPPT and easy replacement; central 1–5 MW units give lower cost per watt for uniform utility arrays"?
A.String vs central inverter — string units up to a few hundred kW give granular MPPT and easy replacement; central 1–5 MW units give lower cost per watt for uniform utility arrays
B.String vs central inverter — GHI is total on a horizontal plane, DNI the direct beam and DHI the diffuse part; most of India receives 4–7 kWh/m² per day
C.String vs central inverter — module power falls about 0.3–0.4% per °C above the 25 °C STC cell temperature, so a 60 °C cell loses 12–14% output
D.String vs central inverter — energy equals load times duration over depth of discharge and round-trip efficiency; LFP cells allow 80–90% DoD over 4000-plus cycles
A.DC/AC ratio — modules in series chosen so Voc at the coldest site temperature stays below the 1000/1500 V limit and Vmp at the hottest stays above MPPT minimum
B.DC/AC ratio — inverter algorithm such as perturb-and-observe or incremental conductance that tracks the knee of the I-V curve where power peaks as irradiance changes
C.DC/AC ratio — inverter loading ratio of 1.2–1.4 oversizes the array to lift capacity utilisation, accepting clipping at peak irradiance
D.DC/AC ratio — grid-code requirements that wind and solar plants ride through low and high voltage, provide reactive support and respond to frequency
A.module power falls about 0.3–0.4% per °C above the 25 °C STC cell temperature, so a 60 °C cell loses 12–14% output
B.modules in series chosen so Voc at the coldest site temperature stays below the 1000/1500 V limit and Vmp at the hottest stays above MPPT minimum
C.string units up to a few hundred kW give granular MPPT and easy replacement; central 1–5 MW units give lower cost per watt for uniform utility arrays
D.inverter loading ratio of 1.2–1.4 oversizes the array to lift capacity utilisation, accepting clipping at peak irradiance
A.Temperature coefficient — energy equals load times duration over depth of discharge and round-trip efficiency; LFP cells allow 80–90% DoD over 4000-plus cycles
B.Temperature coefficient — module power falls about 0.3–0.4% per °C above the 25 °C STC cell temperature, so a 60 °C cell loses 12–14% output
C.Temperature coefficient — string units up to a few hundred kW give granular MPPT and easy replacement; central 1–5 MW units give lower cost per watt for uniform utility arrays
D.Temperature coefficient — inverter algorithm such as perturb-and-observe or incremental conductance that tracks the knee of the I-V curve where power peaks as irradiance changes
A.GHI is total on a horizontal plane, DNI the direct beam and DHI the diffuse part; most of India receives 4–7 kWh/m² per day
B.inverter algorithm such as perturb-and-observe or incremental conductance that tracks the knee of the I-V curve where power peaks as irradiance changes
C.grid-code requirements that wind and solar plants ride through low and high voltage, provide reactive support and respond to frequency
D.energy equals load times duration over depth of discharge and round-trip efficiency; LFP cells allow 80–90% DoD over 4000-plus cycles
23. Which term means: "energy equals load times duration over depth of discharge and round-trip efficiency; LFP cells allow 80–90% DoD over 4000-plus cycles"?
A.BESS sizing — Type 2 DC SPDs at array and inverter plus equipotential bonding of module frames per IEC 62305-3 and IEC 61643
B.BESS sizing — Type 1 fixed-speed induction, Type 2 variable-slip wound rotor, Type 3 DFIG with about 30% partial converter, Type 4 full-converter synchronous
C.BESS sizing — energy equals load times duration over depth of discharge and round-trip efficiency; LFP cells allow 80–90% DoD over 4000-plus cycles
D.BESS sizing — GHI is total on a horizontal plane, DNI the direct beam and DHI the diffuse part; most of India receives 4–7 kWh/m² per day
A.Type 2 DC SPDs at array and inverter plus equipotential bonding of module frames per IEC 62305-3 and IEC 61643
B.modules in series chosen so Voc at the coldest site temperature stays below the 1000/1500 V limit and Vmp at the hottest stays above MPPT minimum
C.module power falls about 0.3–0.4% per °C above the 25 °C STC cell temperature, so a 60 °C cell loses 12–14% output
D.inverter algorithm such as perturb-and-observe or incremental conductance that tracks the knee of the I-V curve where power peaks as irradiance changes
A.PV surge protection — modules in series chosen so Voc at the coldest site temperature stays below the 1000/1500 V limit and Vmp at the hottest stays above MPPT minimum
B.PV surge protection — Type 2 DC SPDs at array and inverter plus equipotential bonding of module frames per IEC 62305-3 and IEC 61643
C.PV surge protection — string units up to a few hundred kW give granular MPPT and easy replacement; central 1–5 MW units give lower cost per watt for uniform utility arrays
D.PV surge protection — inverter algorithm such as perturb-and-observe or incremental conductance that tracks the knee of the I-V curve where power peaks as irradiance changes
29. Which term means: "grid-code requirements that wind and solar plants ride through low and high voltage, provide reactive support and respond to frequency"?
A.CEA connectivity standards for RE — string units up to a few hundred kW give granular MPPT and easy replacement; central 1–5 MW units give lower cost per watt for uniform utility arrays
B.CEA connectivity standards for RE — module power falls about 0.3–0.4% per °C above the 25 °C STC cell temperature, so a 60 °C cell loses 12–14% output
C.CEA connectivity standards for RE — grid-code requirements that wind and solar plants ride through low and high voltage, provide reactive support and respond to frequency
D.CEA connectivity standards for RE — Type 1 fixed-speed induction, Type 2 variable-slip wound rotor, Type 3 DFIG with about 30% partial converter, Type 4 full-converter synchronous
Showing 30 of 33 Renewable & Storage Design questions — the full set, with answers, explanations and an AI tutor on every question, is inside.
Free to start
Answers, AI explanations, and a free readiness check
Sign up free to check your answers with explanations, ask the AI tutor anything on any question, and take the free 2-minute readiness check for a scored result. The full AI mock interview, scored like a real panel, unlocks with Pro.