AI :Introduction (Questions And Answers)

Assignment 1

1. Who said the following - “Thoughts themselves are symbolic representations”?

Isaac Newton

Rene Descartes

Galileo Galilei

Gottfried Wilhelm von Leibniz 

 

Accepted Answers:

Rene Descartes

2. What is true about the Physical Symbol System Hypothesis (PSSH)?

The PSHH says that a physical symbol system has the necessary and sufficient means for general intelligent action.

The PSSH refers to a system with a collection of symbols operated upon by well defined rules.

The PSSH says that the human brain perceives everything as symbols.

The PSSH says that a well defined system of physical signboards is necessary and sufficient to enable intelligent navigation in a city.

Accepted Answers:

The PSHH says that a physical symbol system has the necessary and sufficient means for general intelligent action.

The PSSH refers to a system with a collection of symbols operated upon by well defined rules.

3. Can(Should) natural language be used for knowledge representation in intelligent agents? Why/why not?

Yes. The models of world can be easily expressed, understood and explained in natural language.

No. Natural language is ambiguous and imprecise, and sentences can have more than one meaning.

Yes. The richness of natural language can be used to make more expressive models of the world.

No. It is too verbose and ambiguous to enable sound reasoning in intelligent agents.

Accepted Answers:

No. Natural language is ambiguous and imprecise, and sentences can have more than one meaning.

No. It is too verbose and ambiguous to enable sound reasoning in intelligent agents.

4. Which of the following is(are) true about knowledge representation using formal logics?

Formal logics not only allow knowledge representation but also allow reasoning mechanisms using a set of well defined rules for manipulation of representations.

All logics are equally expressible and hence any logic can be used to model any domain.

More expressive logics lead to more computational complexity.

Classical logics can be extended to capture the notion of time, and are known as temporal logics.

Accepted Answers:

Formal logics not only allow knowledge representation but also allow reasoning mechanisms using a set of well defined rules for manipulation of representations.

More expressive logics lead to more computational complexity.

Classical logics can be extended to capture the notion of time, and are known as temporal logics.

5. A sentence (in formal logic) is a statement that can in principle have a truth value of True or False. Which of the following statements  is a sentence?

Please shut the door.

Do you know who shut the door?

The door is shut.

I shut the door on my gown.

This sentence is false.

Accepted Answers:

The door is shut.

I shut the door on my gown.

6. What do we mean when we say that “a knowledge base entails a sentence α

"?

Accepted Answers:

7. Given a system made up of a logic L with a proof system that can produce ONLY true sentences expressible in L,
          which of the following is (necessarily) true?

The system is Sound and Complete.

The system is Sound but may not be Complete.

The system is Complete but may not be Sound.

The system is neither Sound nor Complete.

Accepted Answers:

The system is Sound but may not be Complete.

8. Given a system made up of a logic L with a proof system that can produce ALL true sentences expressible in L,
         which of the following is (necessarily) true?

The system is Sound and Complete.

The system is Sound but may not be Complete.

The system is Complete but may not be Sound.

The system is neither Sound nor Complete.

Accepted Answers:

The system is Complete but may not be Sound.

9. Which of the following formulas could be a representation of the sentence 'If Sally came for the dance class then she has finished her
          homework or she has a holiday today', where;
        P stands for 'Sally comes for the dance class'        Q stands for 'Sally has finished her homework'        R stands for 'Sally has a holiday today'

Accepted Answers:

10. Which of the following statement is/are a Contingency in propositional logic?

Accepted Answers:

11. Which of the following statement is/are a Tautology in propositional logic? (⊤ represents Top)

Accepted Answers:

12. Which of the following statement is/are a Contradiction in propositional logic? (丄 represents Bottom)

Accepted Answers:

13.

Tautology

Satisfiable

Contradiction

Cannot say

Accepted Answers:

Satisfiable

14. Which of the following can be mapped to formulas in propositional logic? Consider ‘John has X’ as one atomic sentence, and a compound sentence can be broken into equivalent simple sentences.

John has a red hat.

John has a red hat and a red jacket.

If John has a red jacket then he has a red hat too.

John has either a red jacket or a red hat.

John either has a red hat or a red jacket but not both.

Accepted Answers:

John has a red hat.

John has a red hat and a red jacket.

If John has a red jacket then he has a red hat too.

John has either a red jacket or a red hat.

John either has a red hat or a red jacket but not both.

15. What can you say about the truth value of an atomic sentence in propositional logic?

Truth value of an atomic sentences is derived from the knowledge base.

Truth value of atomic sentences is assigned externally by some valuation function.

Truth value of some sentences can be assigned externally by some valuation function and the truth value of the rest of the atomic sentences can be derived later.

None of the above.

Accepted Answers:

Truth value of atomic sentences is assigned externally by some valuation function.

16. Which of the following is not a formula in propositional logic?

Accepted Answers: