100-125 words answer for each. No Plagiarism. Due in 15 hours.

Q1. Explain why the AD curve slopes downward.

Q2. What is the Keynesian multiplier and how does it expand the economy at the rate of the multiple of initial expenditure amount injected into the economy? Give a numerical example as part of your answer.

Q3. Explain briefly why actual unemployment is never zero, even when the economy is considered to be in a state of full employment.

Q4. What were the key sources of the Great Depression of the 1930s? How did the Keynesian economy address the situation for a quick recovery? Explain very briefly.