Hi , As a fresher or Experience Testers you Should know all the answer   it  will cover 99% of Theory of Testing Job Interview question   :-

 Basics

What Is Testing ?
Purpose of Testing
Software Testing Principles
Test Case Structure
Test Procedure and Test Report
Explain about Error, Fault and Failure
What Must be Included in Test Specification ?
Test Estimation
When Testing Completes ?
What are Objectives of Software Tester ?
Software Testing - Do's and Dont's
Test Case Design - Do's and Don'ts

Testing Levels :

 Unit testing
Integration testing
System testing
Acceptance testing
     Verification and Validation :
What is Verification ?
What is Validation ?
Verification vs. Validation
V & V Process And Goals

Types Of Software Testing

What is Black Box Testing ?
What is White Box Testing ?
What is Unit Testing ?
What is Smoke Testing ?
What is Security Testing ?
What is StressTesting ?
What is Alpha Testing ?
What is Sanity Testing ?
What is Mutation Testing ?
What is End-to-End Testing ?
What is Conversion Testing ?
What is Incremental Testing ?
What is Volume Testing ?
What is Usability Testing ?
What is Integration Testing ?
What is Regression Testing ?
What is User Acceptance Testing ?
What is Recovery Testing ?
What is Performance Testing ?
What is System Testing ?
What is Beta Testing ?
What is Load Testing ?
What is Perturbation Testing ?
What is Installation Testing ?
What is Configuration Testing ?
What is Ad hoc Testing ?
What is Functional Testing ?
What is Concurrency Testing ?

Life Cycle Models :

 Agile Model
Water fall model
Spiral Model
V - Model
Prototype Model
Incremental Model
Rapid Action Development Model

Quality Assurance and Quality Control : 

What is Quality ?
Quality Principles
What is difference between Quality Assurance and Quality Control
Responsibilities of Quality Assurance and Quality Control
Explain Versions, Variants and Releases ?
Severity Vs Priority