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IN Plumber practice questions

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Question 1General Regulations, Permits, and Licensing Administration

Which state entity administers the licensing of plumbers in Indiana?

  1. The Indiana Professional Licensing Agency Correct answer.
  2. The Indiana State Department of Health
  3. The Indiana Department of Transportation
  4. The Indiana Utility Regulatory Commission

Explanation

Plumber licensing is administered through the Indiana Professional Licensing Agency, which provides staff support to the Indiana Plumbing Commission. The commission sets licensing policy and hears disciplinary matters, while the agency carries out day-to-day licensing functions such as applications and renewals. Transportation, utility, and health agencies have no role in licensing plumbers.

Question 2General Regulations, Permits, and Licensing Administration

Under Indiana's plumbing regulations, at what point must a permit be obtained for plumbing work that requires one?

  1. Within ten days after the work begins
  2. After the rough-in piping is installed
  3. Before any work begins Correct answer.
  4. Before the final inspection is requested

Explanation

A plumbing permit must be secured before work starts so the installation can be inspected at the required stages, including rough-in. Applying after work has begun deprives the authority of the chance to inspect concealed piping and may draw additional fees or enforcement action.

Question 3General Regulations, Permits, and Licensing Administration

Who issues a plumbing permit for a project in a local jurisdiction?

  1. The Indiana Plumbing Commission
  2. The Indiana Department of Environmental Management
  3. The local building official with jurisdiction Correct answer.
  4. The water utility serving the property

Explanation

Permits are issued by the local authority having jurisdiction, usually a city or county building department that enforces the state plumbing code locally. The state commission licenses plumbers and handles discipline but does not issue permits for individual projects.

Question 4General Regulations, Permits, and Licensing Administration

What is the primary purpose of the final plumbing inspection?

  1. To verify completed work meets code Correct answer.
  2. To confirm the contractor's license is current
  3. To decide which fixtures the owner may install
  4. To set the permit fee for the project

Explanation

The final inspection confirms that the completed installation, including fixtures, connections, and testing, complies with the adopted plumbing code before the system is approved for use. Licensing and fee questions are handled administratively rather than through the inspection itself.

Question 5General Regulations, Permits, and Licensing Administration

Which body adopts the Indiana Plumbing Code that local jurisdictions enforce?

  1. The Indiana Plumbing Commission
  2. The Indiana General Assembly
  3. The Indiana Department of Health
  4. The Fire Prevention and Building Safety Commission Correct answer.

Explanation

The Indiana Plumbing Code is adopted as administrative rules by the Fire Prevention and Building Safety Commission within the state's fire and building safety structure, and local building officials enforce it. The Plumbing Commission licenses and disciplines plumbers but does not write the plumbing code.

Question 6General Regulations, Permits, and Licensing Administration

The Indiana Plumbing Code is substantially based on which model plumbing code?

  1. The Uniform Plumbing Code Correct answer.
  2. The National Plumbing Code of Canada
  3. The National Standard Plumbing Code
  4. The International Plumbing Code

Explanation

Indiana's plumbing rules adopt the Uniform Plumbing Code, published by IAPMO, together with Indiana amendments. The International Plumbing Code and the National Standard Plumbing Code are model codes relied on in other jurisdictions, not the base document for Indiana's plumbing rules.

Question 7General Regulations, Permits, and Licensing Administration

Which license must a business hold to contract with the public for the installation of plumbing in Indiana?

  1. An apprentice plumber registration
  2. A plumbing supply dealer license
  3. A plumbing contractor license Correct answer.
  4. A journeyman plumber license

Explanation

The plumbing contractor license is the business-level credential that authorizes offering and performing plumbing contracting services to the public. Journeyman and apprentice credentials authorize individuals to perform plumbing work but do not permit them to contract for it independently.

Question 8General Regulations, Permits, and Licensing Administration

Under what condition may an apprentice plumber perform plumbing work?

  1. Only when the work will not be inspected
  2. Only after passing the journeyman examination
  3. Only on single-family dwellings
  4. Only under the supervision of a licensed plumber Correct answer.

Explanation

Apprentices learn the trade by performing plumbing work under the supervision of a licensed plumber while accumulating the experience needed for journeyman licensure. They may not perform plumbing work independently or act as the responsible person on a permit.

Question 9General Regulations, Permits, and Licensing Administration

A person who performs plumbing work for pay without holding the required Indiana license is subject to which of the following?

  1. A permit surcharge paid to the state
  2. A warning letter only for a first offense
  3. No action if the work passes inspection
  4. Disciplinary and civil enforcement action Correct answer.

Explanation

Performing plumbing work without the required license is unlicensed practice, which can be pursued through civil penalties, cease-and-desist action, and other enforcement measures. A successful inspection does not cure the absence of a license.

Question 10General Regulations, Permits, and Licensing Administration

When should the rough-in inspection of a plumbing system be requested?

  1. After the building is occupied
  2. After the walls and ceilings are finished
  3. After the piping is installed and tested but before it is covered Correct answer.
  4. After the fixtures are set and connected

Explanation

Rough-in inspection must take place while the piping is still exposed, after installation and the required tests, so the inspector can verify joints, supports, and slopes. Covering the piping before that inspection prevents the work from being verified.

Question 11General Regulations, Permits, and Licensing Administration

If a permit holder covers plumbing work before it has been inspected and approved, what may the authority having jurisdiction require?

  1. That the owner sign a liability waiver
  2. That the permit be converted to a repair permit
  3. Nothing, if the work is later found to be correct
  4. That the work be uncovered for inspection Correct answer.

Explanation

Work that will be concealed must be inspected before it is covered; if it is covered prematurely, the inspector may require the permit holder to expose it at the permit holder's expense. Approval of later stages may be withheld until the concealed work has been examined.

Question 12General Regulations, Permits, and Licensing Administration

A plumbing contractor who holds a permit for a project is replaced by a different contractor. What is generally required?

  1. The permit must be reissued or transferred Correct answer.
  2. The owner must obtain a new building permit only
  3. The original permit stays valid for the new contractor
  4. The new contractor may proceed with no permit action

Explanation

A plumbing permit is issued to a specific permit holder and is not automatically assigned to a different contractor. When the contractor of record changes, the authority having jurisdiction must approve a transfer or issue a new permit so that responsibility for the work remains clear.

Question 13General Regulations, Permits, and Licensing Administration

On a permitted plumbing project, who is responsible for requesting the required inspections?

  1. The local building department, on its own schedule
  2. The fixture supplier named on the plans
  3. The permit holder or an authorized representative Correct answer.
  4. The utility that provides water service

Explanation

The permit holder, typically the licensed contractor, must notify the authority when the work is ready for inspection; inspectors do not routinely monitor job sites for readiness. Failing to request an inspection leaves the work unapproved and can stall later stages of the project.

Question 14General Regulations, Permits, and Licensing Administration

How may an applicant licensed as a plumber in another state qualify for an Indiana license?

  1. Through license reciprocity Correct answer.
  2. By submitting letters of recommendation from plumbers
  3. By paying an additional fee instead of taking the examination
  4. By working one year in Indiana without a license

Explanation

Indiana law allows the commission to license applicants who hold equivalent credentials from another state, typically through reciprocity or endorsement, when the other state's requirements are substantially comparable. The other routes do not substitute for meeting Indiana's licensing requirements.

Question 15General Regulations, Permits, and Licensing Administration

A plumber whose Indiana license has expired continues to perform plumbing work. How is this treated?

  1. As a minor violation cured by paying a late fee
  2. As allowed if the employer holds a contractor license
  3. As permitted, provided renewal is completed within the year
  4. As unlicensed practice subject to enforcement Correct answer.

Explanation

When a license expires, the privilege to practice ends, and work performed afterward is unlicensed practice until the license is renewed or reinstated. A late fee may be needed to renew, but it does not retroactively authorize work done while the license had lapsed.

Question 16General Regulations, Permits, and Licensing Administration

Which of the following is a ground on which the Indiana Plumbing Commission may discipline a licensee?

  1. Refusing work outside the licensee's expertise
  2. Charging more than the local average price
  3. Obtaining a license through fraud or misrepresentation Correct answer.
  4. Filing a lien for unpaid work

Explanation

Fraud or misrepresentation in obtaining or renewing a license is a standard ground for disciplinary action, along with incompetence, code violations, and similar misconduct. Pricing decisions and declining work outside one's competence are business judgments that fall outside the commission's disciplinary authority.

Question 17Definitions and General Building Supply and Drainage Requirements

In plumbing terminology, a stack is best described as:

  1. A fitting used to join pipes of different diameters
  2. A device for measuring the flow of water in a supply pipe
  3. A vertical pipe with branches carrying water or waste Correct answer.
  4. Any pipe laid below ground level

Explanation

A stack is a vertical line of piping that has one or more branches and carries water, soil or waste from floor to floor. Horizontal runs that collect fixture discharge are called branches or drains, and the below-ground collector is the building drain.

Question 18Definitions and General Building Supply and Drainage Requirements

For domestic buildings, the per capita water demand commonly adopted for design of the supply system is:

  1. 135 litres per capita per day Correct answer.
  2. 450 litres per capita per day
  3. 210 litres per capita per day
  4. 45 litres per capita per day

Explanation

Indian practice adopts about 135 litres per capita per day for domestic buildings, covering drinking, cooking, bathing, washing and flushing. This figure is used to size storage tanks, service pipes and the source.

Question 19Definitions and General Building Supply and Drainage Requirements

The minimum depth of water seal required in a trap is:

  1. 150 mm
  2. 50 mm Correct answer.
  3. 10 mm
  4. 25 mm

Explanation

A trap must retain a water seal of at least 50 mm to resist pressure fluctuations in the drainage system and keep foul air out. Seals shallower than this are easily broken by siphonage or evaporation.

Question 20Definitions and General Building Supply and Drainage Requirements

A fixture unit is a measure of:

  1. The water pressure needed at the fixture
  2. The number of people who use the fixture
  3. The physical size of the fixture
  4. The probable discharge load of the fixture Correct answer.

Explanation

The fixture unit is a dimensionless measure of the probable rate of discharge a fixture contributes to the drainage system, taking into account its volume and the interval between uses. Fixture units are summed to size branches, stacks and drains.

Question 21Definitions and General Building Supply and Drainage Requirements

A pipe that carries the discharge from water closets and urinals is known as a:

  1. Soil pipe Correct answer.
  2. Vent pipe
  3. Rainwater pipe
  4. Waste pipe

Explanation

A soil pipe conveys sewage that contains faecal matter, such as the discharge from water closets and urinals. Waste pipes carry discharges free of faecal matter, for example from basins, sinks and baths.

Question 22Definitions and General Building Supply and Drainage Requirements

Lead pipe is not permitted for conveying drinking water mainly because:

  1. It cannot withstand normal supply pressures
  2. It corrodes very quickly in hard water
  3. It is difficult to bend and install
  4. Lead dissolves in soft water and is toxic Correct answer.

Explanation

Soft, slightly acidic water dissolves lead from the pipe wall, and ingested lead accumulates in the body and causes serious poisoning. For this reason lead is prohibited for potable water lines and other materials are used.

Question 23Definitions and General Building Supply and Drainage Requirements

The gradient normally adopted for a 100 mm diameter horizontal soil drain to keep it self-cleansing is about:

  1. 1 in 250
  2. 1 in 15
  3. 1 in 5
  4. 1 in 60 Correct answer.

Explanation

A 100 mm drain is laid at about 1 in 60 (with about 1 in 100 for a 150 mm drain) so that sewage flows fast enough to carry solids without scouring. The gradient balances self-cleansing velocity against excessive slope.

Question 24Definitions and General Building Supply and Drainage Requirements

Before backfilling a newly laid underground drainage line, its watertightness is usually established by a:

  1. Water test Correct answer.
  2. Air test
  3. Smoke test
  4. Ball test

Explanation

In the water test the section of drain is sealed, filled with water to the required head and inspected for loss of water or visible leakage. This is the standard acceptance test applied to new underground pipework before it is covered.

Question 25Definitions and General Building Supply and Drainage Requirements

The smallest nominal size of drain that may receive the discharge of a water closet is:

  1. 100 mm Correct answer.
  2. 150 mm
  3. 65 mm
  4. 50 mm

Explanation

A water closet has a nominal 100 mm outlet and trapway, so the drain it discharges into must be at least 100 mm to pass solids and to match the fixture outlet. Smaller sizes are appropriate only for fixtures such as basins and sinks.

Question 26Definitions and General Building Supply and Drainage Requirements

The water seal of a trap serving a fixture that is rarely used is most likely to be lost by:

  1. Momentum of the moving water
  2. Evaporation of water from the seal Correct answer.
  3. Back pressure from the public sewer
  4. Foaming of the waste water

Explanation

When a fixture is not used for a long period there is no replenishment, and the thin body of water in the trap simply evaporates. Back pressure and siphonage affect traps in active use, whereas evaporation governs idle fixtures.

Question 27Definitions and General Building Supply and Drainage Requirements

An intercepting trap with a fresh-air inlet is provided:

  1. Directly beneath each kitchen sink in the building
  2. At the open terminal of the vent stack above the roof
  3. Between the building drain and the public sewer Correct answer.
  4. At the foot of every soil stack in the building

Explanation

The intercepting trap is placed in the house drain just before it joins the public sewer, and its fresh-air inlet ventilates that point. It prevents foul air and gases from the sewer from entering the building drainage system.

Question 28Definitions and General Building Supply and Drainage Requirements

A grease trap is required in the drainage system serving:

  1. Urinals in a public convenience
  2. Sinks of a commercial kitchen Correct answer.
  3. Rainwater downpipes from the roof
  4. Water closets in public toilets

Explanation

Grease and oil in kitchen waste congeal in the drain and cause blockages, so a grease trap is installed to intercept it before the waste enters the system. It is required for commercial kitchens and similar food-handling establishments.

Question 29Definitions and General Building Supply and Drainage Requirements

The simplest and most dependable method of preventing backflow of contaminated water into a potable supply is:

  1. A strainer and float valve fitted at the fixture inlet
  2. A non-return valve fitted on the supply pipe near the fixture
  3. A physical air gap between the outlet and flood level Correct answer.
  4. A pressure reducing valve installed on the branch supply

Explanation

An air gap provides a physical separation between the supply outlet and the flood level of the fixture, so that no back siphonage is possible even if pressure in the main falls. It needs no moving parts and therefore does not rely on maintenance for its protection.

Question 30Definitions and General Building Supply and Drainage Requirements

Back venting (re-venting) is provided for fixtures grouped on a long horizontal branch in order to:

  1. Increase the velocity of flow in the horizontal branch
  2. Prevent self-siphonage of trap seals on a long branch Correct answer.
  3. Reduce the diameter of the branch and the stack
  4. Allow the branch to be laid at a flatter gradient

Explanation

On a long branch, discharge from fixtures near the stack can fill the pipe and induce a partial vacuum that siphons the traps of fixtures further along. A back vent admits air close to those traps and so protects their seals.

Question 31Definitions and General Building Supply and Drainage Requirements

A 50 mm branch about 6 m long serves a single washbasin. It drains slowly and the basin trap gurgles at the end of discharge. The most probable cause is:

  1. The branch is unvented and the trap is self-siphoned Correct answer.
  2. The branch gradient is too steep at 1 in 60
  3. The trap seal is deeper than the 50 mm minimum
  4. The fixture is connected to a soil stack instead of a waste stack

Explanation

Gurgling followed by slow drainage indicates that the trap seal has been drawn out by the partial vacuum created as the long branch discharges. The remedy is to vent the branch close to the fixture so that air can enter and equalise the pressure.

Question 32Definitions and General Building Supply and Drainage Requirements

In the single-stack system of plumbing, one pipe carries the discharge from the building's fixtures, which is best described as:

  1. Two separate stacks, one for soil and one for waste, with no vent pipe
  2. A separate stack for each floor, all discharging into a common collector
  3. A single stack that carries both soil and waste, with a separate vent pipe Correct answer.
  4. A single stack that carries only soil and is connected to an open drain

Explanation

In the single-stack system one vertical pipe receives both soil and waste, and a separate vent pipe runs alongside it to relieve pressure and protect trap seals. It uses less pipework and space than the two-pipe system, where soil and waste are carried in separate stacks.

Question 33Water Supply and Distribution

A threaded hose bibb on the outside of a house is best protected against backflow by installing which device?

  1. A hose bibb vacuum breaker Correct answer.
  2. A thermal expansion tank
  3. A pressure reducing valve
  4. A double check valve assembly

Explanation

A hose bibb vacuum breaker threads onto the bibb and opens to atmosphere when supply pressure drops, breaking any siphon that could pull contaminants back into the potable line. It is a small, inexpensive device intended specifically for sillcocks.

Question 34Water Supply and Distribution

Which material is commonly joined with lead-free solder or press fittings and is widely used for interior potable water piping?

  1. Copper Correct answer.
  2. PVC
  3. ABS
  4. Cast iron

Explanation

Copper tube is joined with lead-free solder or mechanical press tools and is a standard material for potable water distribution inside a building. PVC and ABS are joined with solvent cement and are generally limited to cold water or non-potable uses, while cast iron is a drain, waste, and vent material.

Question 35Water Supply and Distribution

Where is a residential water meter normally installed?

  1. On the service line at the building entry Correct answer.
  2. Inside the pressure tank
  3. At the water heater inlet
  4. At the highest fixture served in the building

Explanation

The meter is set on the service line, usually in a meter box near the building entry or property line, so that all water entering the building is measured. Placing it there also makes it accessible for reading and service.

Question 36Water Supply and Distribution

What is the primary purpose of a pressure reducing valve on a municipal water service?

  1. To boost pressure at upper floors
  2. To reduce high incoming pressure Correct answer.
  3. To measure the volume of water used
  4. To trap debris ahead of the meter

Explanation

A pressure reducing valve is a regulator that lowers street pressure to a set downstream value, protecting fixtures, appliances, and piping from excessive pressure. It does not add pressure or measure flow.

Question 37Water Supply and Distribution

Which valve is normally used to isolate a section of water main and is operated either fully open or fully closed?

  1. Globe valve
  2. Gate valve Correct answer.
  3. Pressure relief valve
  4. Needle valve

Explanation

Gate valves are designed for isolation service and offer low pressure loss when fully open, so they are used fully open or fully closed. Globe and needle valves are intended for throttling flow.

Question 38Water Supply and Distribution

Water hammer is a pressure surge most often caused by...

  1. A leaking flapper in the toilet tank
  2. Air trapped inside the water heater
  3. Excessive hardness in the water
  4. A quick-closing valve stopping flow Correct answer.

Explanation

When flow is stopped abruptly, the momentum of the moving water produces a pressure wave that travels through the piping and can be heard as a bang. Arrestors or slow-closing valves reduce this surge.

Question 39Water Supply and Distribution

A check valve installed in a water supply line allows flow in...

  1. One direction only Correct answer.
  2. The downward direction only
  3. Only when pressure exceeds 100 psi
  4. Both directions

Explanation

A check valve is a one-way valve that opens with forward flow and closes when flow reverses, protecting pumps and preventing backflow. Its action depends on flow direction, not on a fixed pressure threshold.

Question 40Water Supply and Distribution

Water softeners remove hardness minerals primarily by...

  1. Passing it through a sand filter
  2. Chlorinating the water
  3. Ion exchange Correct answer.
  4. Boiling the water

Explanation

Hardness is mainly calcium and magnesium, which are exchanged for sodium or potassium ions on a resin bed as the water passes through the softener. Boiling, chlorination, and sand filtration do not remove those minerals.

Question 41Water Supply and Distribution

A water main has a static pressure of 60 psi at street level. Ignoring friction, what is the approximate static pressure at a fixture 20 feet above street level?

  1. 43 psi
  2. 69 psi
  3. 51 psi Correct answer.
  4. 60 psi

Explanation

Static pressure changes about 0.433 psi per foot of elevation. A 20-foot rise reduces pressure by 20 times 0.433, or about 8.7 psi, so the pressure is roughly 60 minus 8.7, or 51 psi.

Question 42Water Supply and Distribution

Why are municipal distribution mains often arranged in a looped grid rather than a branching tree?

  1. To reduce the pipe diameter required
  2. To keep pressure during section shutdowns Correct answer.
  3. To raise the chlorine demand of the water
  4. To eliminate the need for valves entirely

Explanation

A looped grid gives water more than one path to reach a customer, so pressure and service are maintained when a section is isolated for repair. Branching systems create dead ends and leave all downstream users without water during a shutdown.

Question 43Water Supply and Distribution

A dielectric union is installed where copper pipe connects to galvanized steel pipe in order to...

  1. Allow the joint to be taken apart under pressure
  2. Absorb thermal expansion
  3. Increase flow velocity
  4. Prevent galvanic corrosion Correct answer.

Explanation

Dissimilar metals in contact with water form a galvanic cell in which the less noble metal, here the steel, corrodes. A dielectric union separates the metals electrically and stops that corrosion.

Question 44Water Supply and Distribution

A reduced pressure zone assembly is required where the potential hazard is classified as...

  1. Low hazard
  2. Low and moderate hazard
  3. High hazard Correct answer.
  4. No hazard

Explanation

The reduced pressure zone assembly has two independent check valves plus a relief valve and is rated for high-hazard protection against both backpressure and backsiphonage. Low-hazard protection can be provided by less protective devices such as a double check assembly.

Question 45Water Supply and Distribution

A thermal expansion tank is needed on a potable water system when...

  1. The supply pressure is under 40 psi
  2. A water softener is installed on the line
  3. The system is closed at the water heater Correct answer.
  4. The building is on a private well

Explanation

When a check valve, backflow preventer, or pressure reducing valve prevents water from expanding back into the main, heating the water raises system pressure. The expansion tank gives the expanding water a place to go.

Question 46Water Supply and Distribution

Which sequence shows the correct order of components from the main toward the building?

  1. Curb stop, meter, corporation stop, service line
  2. Service line, corporation stop, meter, curb stop
  3. Corporation stop, service line, curb stop, meter Correct answer.
  4. Meter, corporation stop, curb stop, service line

Explanation

The corporation stop is tapped into the main, the service line runs from it to the curb stop at the property line, and the meter sits downstream near the building. Flow therefore passes the corporation stop first and the meter last.

Question 47Water Supply and Distribution

Residual pressure in a water distribution system is the pressure...

  1. Inside the water heater tank
  2. Remaining during flow at a point Correct answer.
  3. Created by the water softener unit
  4. Measured when no water is flowing

Explanation

Static pressure is read with no flow, while residual pressure is what remains at a point while water is moving, after friction and elevation losses are subtracted. Low residual pressure at a fixture indicates excessive loss in the piping or service.

Question 48Water Supply and Distribution

The main function of a pressure tank on a private well system is to...

  1. Hold pressure and cut pump cycling Correct answer.
  2. Soften the water for the whole house
  3. Raise the well pump's flow rate
  4. Remove fine sediment from the water supply

Explanation

The tank stores water under air pressure so the pump does not start every time a fixture opens, and it keeps pressure steady between pump cycles. It does not treat water or change the pump's capacity.

Question 49Water Supply and Distribution

Which fitting is used to connect a new service line to a live water main without shutting the main down?

  1. A dielectric union
  2. A pressure relief valve
  3. A corporation stop Correct answer.
  4. A swing check valve

Explanation

A corporation stop, often installed with a tapping saddle, is screwed or clamped into a pressurized main and controls flow to the new service until the connection is complete. This allows a tap to be made without interrupting service to other customers.

Question 50Water Supply and Distribution

After a new water main is disinfected and flushed, what must be done before it is placed in service?

  1. Filled with compressed air and capped
  2. Painted inside and out with epoxy
  3. Sampled for bacteria and chlorine residual Correct answer.
  4. Coated internally with cement mortar

Explanation

Flushing clears heavily chlorinated water and debris, and bacteriological samples plus a chlorine residual test confirm the main is safe to put into service. Sampling is the step that verifies disinfection worked.