FLORIDA PLUMBING CONTRACTOR
LICENSE EXAM | COMPLETE EXAM BANK
WITH CORRECT ANSWERS AND EXPERT
RATIONALES
What is the minimum slope for a 2-inch horizontal
drain pipe?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Correct Answer: B
Rationale: NEC and IPC require 1/4 inch per foot to
ensure proper drainage and prevent clogs.
What is the primary purpose of a vent pipe in
plumbing?
A. Prevent sewer gas from entering the building
B. Increase water pressure
C. Drain water faster
D. Support pipes
Correct Answer: A
,Rationale: Vent pipes equalize pressure in the
drainage system and prevent siphoning of traps.
What is a P-trap used for?
A. Prevent sewer gases from entering the building
B. Increase water pressure
C. Provide a cleanout
D. Connect water supply lines
Correct Answer: A
Rationale: The water in the trap acts as a barrier to
sewer gases.
What is the maximum distance a trap arm can run
before a vent is required for a 1 1/4-inch pipe?
A. 5 feet
B. 6 feet
C. 8 feet
D. 10 feet
Correct Answer: B
Rationale: IPC limits trap arm length to ensure proper
drainage and prevent siphoning.
,What is the purpose of a backflow preventer?
A. Stop contaminated water from entering potable
supply
B. Increase pressure
C. Drain water faster
D. Vent the system
Correct Answer: A
Rationale: Prevents cross-contamination between
potable and non-potable water systems.
What is the minimum water pressure required at a
residential fixture?
A. 15 psi
B. 20 psi
C. 30 psi
D. 50 psi
Correct Answer: B
Rationale: Ensures proper fixture operation without
excessive pressure.
What is the maximum distance between supports for
3/4-inch copper water pipe?
, A. 6 feet
B. 8 feet
C. 10 feet
D. 12 feet
Correct Answer: A
Rationale: Prevents sagging and damage to pipes per
IPC.
What is the purpose of a cleanout?
A. Allow access to clear clogs in drains
B. Increase water pressure
C. Vent the system
D. Connect water supply
Correct Answer: A
Rationale: Provides maintenance access for
blockages in the drainage system.
What is the minimum size for a residential water
service pipe?
A. 3/4 inch
B. 1 inch
C. 1 1/4 inch
LICENSE EXAM | COMPLETE EXAM BANK
WITH CORRECT ANSWERS AND EXPERT
RATIONALES
What is the minimum slope for a 2-inch horizontal
drain pipe?
A. 1/8 inch per foot
B. 1/4 inch per foot
C. 1/2 inch per foot
D. 1 inch per foot
Correct Answer: B
Rationale: NEC and IPC require 1/4 inch per foot to
ensure proper drainage and prevent clogs.
What is the primary purpose of a vent pipe in
plumbing?
A. Prevent sewer gas from entering the building
B. Increase water pressure
C. Drain water faster
D. Support pipes
Correct Answer: A
,Rationale: Vent pipes equalize pressure in the
drainage system and prevent siphoning of traps.
What is a P-trap used for?
A. Prevent sewer gases from entering the building
B. Increase water pressure
C. Provide a cleanout
D. Connect water supply lines
Correct Answer: A
Rationale: The water in the trap acts as a barrier to
sewer gases.
What is the maximum distance a trap arm can run
before a vent is required for a 1 1/4-inch pipe?
A. 5 feet
B. 6 feet
C. 8 feet
D. 10 feet
Correct Answer: B
Rationale: IPC limits trap arm length to ensure proper
drainage and prevent siphoning.
,What is the purpose of a backflow preventer?
A. Stop contaminated water from entering potable
supply
B. Increase pressure
C. Drain water faster
D. Vent the system
Correct Answer: A
Rationale: Prevents cross-contamination between
potable and non-potable water systems.
What is the minimum water pressure required at a
residential fixture?
A. 15 psi
B. 20 psi
C. 30 psi
D. 50 psi
Correct Answer: B
Rationale: Ensures proper fixture operation without
excessive pressure.
What is the maximum distance between supports for
3/4-inch copper water pipe?
, A. 6 feet
B. 8 feet
C. 10 feet
D. 12 feet
Correct Answer: A
Rationale: Prevents sagging and damage to pipes per
IPC.
What is the purpose of a cleanout?
A. Allow access to clear clogs in drains
B. Increase water pressure
C. Vent the system
D. Connect water supply
Correct Answer: A
Rationale: Provides maintenance access for
blockages in the drainage system.
What is the minimum size for a residential water
service pipe?
A. 3/4 inch
B. 1 inch
C. 1 1/4 inch
