Schema & Types interview questions

27 real Schema & Types questions from the GraphQL 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 Schema?

Junior
  1. A.the typed contract defining every queryable type, field and operation an API exposes to clients
  2. B.an abstract type listing fields that multiple object types must each implement, enabling shared polymorphic selections
  3. C.a named type made up of fields, each returning a scalar or another type, that models an entity in the graph
  4. D.a serialized-as-String scalar intended to be a unique, often opaque, identifier for an object and not human-readable
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3. Which statement is correct?

Junior
  1. A.Schema — a special object-like type used only to pass structured argument data into operations, never returned in results
  2. B.Schema — a named type made up of fields, each returning a scalar or another type, that models an entity in the graph
  3. C.Schema — an abstract type listing fields that multiple object types must each implement, enabling shared polymorphic selections
  4. D.Schema — the typed contract defining every queryable type, field and operation an API exposes to clients
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4. What is Object type?

Junior
  1. A.an abstract type whose value is exactly one of several listed object types that need share no common fields
  2. B.a special object-like type used only to pass structured argument data into operations, never returned in results
  3. C.a named type made up of fields, each returning a scalar or another type, that models an entity in the graph
  4. D.a serialized-as-String scalar intended to be a unique, often opaque, identifier for an object and not human-readable
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6. Which statement is correct?

Junior
  1. A.Object type — a special object-like type used only to pass structured argument data into operations, never returned in results
  2. B.Object type — a serialized-as-String scalar intended to be a unique, often opaque, identifier for an object and not human-readable
  3. C.Object type — a named type made up of fields, each returning a scalar or another type, that models an entity in the graph
  4. D.Object type — a type restricting a field to a fixed, predefined set of named string values
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7. What is Scalar?

Junior
  1. A.the typed contract defining every queryable type, field and operation an API exposes to clients
  2. B.an abstract type whose value is exactly one of several listed object types that need share no common fields
  3. C.a user-defined leaf type, like DateTime, with its own serialization and validation logic beyond the built-in primitives
  4. D.a leaf value type such as Int, Float, String, Boolean or ID that resolves to a concrete primitive
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9. Which statement is correct?

Junior
  1. A.Scalar — an abstract type whose value is exactly one of several listed object types that need share no common fields
  2. B.Scalar — a leaf value type such as Int, Float, String, Boolean or ID that resolves to a concrete primitive
  3. C.Scalar — a named type made up of fields, each returning a scalar or another type, that models an entity in the graph
  4. D.Scalar — the typed contract defining every queryable type, field and operation an API exposes to clients
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10. What is ID type?

Junior
  1. A.a serialized-as-String scalar intended to be a unique, often opaque, identifier for an object and not human-readable
  2. B.the typed contract defining every queryable type, field and operation an API exposes to clients
  3. C.a user-defined leaf type, like DateTime, with its own serialization and validation logic beyond the built-in primitives
  4. D.an abstract type whose value is exactly one of several listed object types that need share no common fields
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12. Which statement is correct?

Junior
  1. A.ID type — a named type made up of fields, each returning a scalar or another type, that models an entity in the graph
  2. B.ID type — a serialized-as-String scalar intended to be a unique, often opaque, identifier for an object and not human-readable
  3. C.ID type — a special object-like type used only to pass structured argument data into operations, never returned in results
  4. D.ID type — a leaf value type such as Int, Float, String, Boolean or ID that resolves to a concrete primitive
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13. What is Input type?

Mid
  1. A.the typed contract defining every queryable type, field and operation an API exposes to clients
  2. B.a leaf value type such as Int, Float, String, Boolean or ID that resolves to a concrete primitive
  3. C.an abstract type whose value is exactly one of several listed object types that need share no common fields
  4. D.a special object-like type used only to pass structured argument data into operations, never returned in results
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15. Which statement is correct?

Mid
  1. A.Input type — a user-defined leaf type, like DateTime, with its own serialization and validation logic beyond the built-in primitives
  2. B.Input type — an abstract type listing fields that multiple object types must each implement, enabling shared polymorphic selections
  3. C.Input type — a special object-like type used only to pass structured argument data into operations, never returned in results
  4. D.Input type — an abstract type whose value is exactly one of several listed object types that need share no common fields
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16. What is Enum?

Junior
  1. A.a leaf value type such as Int, Float, String, Boolean or ID that resolves to a concrete primitive
  2. B.a user-defined leaf type, like DateTime, with its own serialization and validation logic beyond the built-in primitives
  3. C.an abstract type listing fields that multiple object types must each implement, enabling shared polymorphic selections
  4. D.a type restricting a field to a fixed, predefined set of named string values
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18. Which statement is correct?

Junior
  1. A.Enum — a leaf value type such as Int, Float, String, Boolean or ID that resolves to a concrete primitive
  2. B.Enum — an abstract type listing fields that multiple object types must each implement, enabling shared polymorphic selections
  3. C.Enum — a named type made up of fields, each returning a scalar or another type, that models an entity in the graph
  4. D.Enum — a type restricting a field to a fixed, predefined set of named string values
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19. What is Interface?

Mid
  1. A.a special object-like type used only to pass structured argument data into operations, never returned in results
  2. B.the typed contract defining every queryable type, field and operation an API exposes to clients
  3. C.an abstract type whose value is exactly one of several listed object types that need share no common fields
  4. D.an abstract type listing fields that multiple object types must each implement, enabling shared polymorphic selections
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21. Which statement is correct?

Mid
  1. A.Interface — an abstract type listing fields that multiple object types must each implement, enabling shared polymorphic selections
  2. B.Interface — a leaf value type such as Int, Float, String, Boolean or ID that resolves to a concrete primitive
  3. C.Interface — a user-defined leaf type, like DateTime, with its own serialization and validation logic beyond the built-in primitives
  4. D.Interface — the typed contract defining every queryable type, field and operation an API exposes to clients
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22. What is Union?

Mid
  1. A.a serialized-as-String scalar intended to be a unique, often opaque, identifier for an object and not human-readable
  2. B.a named type made up of fields, each returning a scalar or another type, that models an entity in the graph
  3. C.the typed contract defining every queryable type, field and operation an API exposes to clients
  4. D.an abstract type whose value is exactly one of several listed object types that need share no common fields
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24. Which statement is correct?

Mid
  1. A.Union — a special object-like type used only to pass structured argument data into operations, never returned in results
  2. B.Union — the typed contract defining every queryable type, field and operation an API exposes to clients
  3. C.Union — an abstract type whose value is exactly one of several listed object types that need share no common fields
  4. D.Union — a type restricting a field to a fixed, predefined set of named string values
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25. What is Custom scalar?

Senior
  1. A.a leaf value type such as Int, Float, String, Boolean or ID that resolves to a concrete primitive
  2. B.the typed contract defining every queryable type, field and operation an API exposes to clients
  3. C.a user-defined leaf type, like DateTime, with its own serialization and validation logic beyond the built-in primitives
  4. D.a type restricting a field to a fixed, predefined set of named string values
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27. Which statement is correct?

Senior
  1. A.Custom scalar — an abstract type whose value is exactly one of several listed object types that need share no common fields
  2. B.Custom scalar — a type restricting a field to a fixed, predefined set of named string values
  3. C.Custom scalar — a user-defined leaf type, like DateTime, with its own serialization and validation logic beyond the built-in primitives
  4. D.Custom scalar — a special object-like type used only to pass structured argument data into operations, never returned in results
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