KMU Past Paper Practice

Question:

A pistol cartridge is examined after repeated failure to discharge. The firing pin has struck the cartridge, but the propellant has not ignited. Failure of which component most directly explains this malfunction?

Options:

Correct Answer: Primer

Explanation: The firing pin normally strikes the primer, which ignites the propellant. Primer failure prevents the pressure-generating combustion sequence.

Question:

During examination of two discharged firearms, one produces heavy smoke and abundant solid residue, while the other produces much less visible smoke. Which propellant was most likely used in the first firearm?

Options:

Correct Answer: Black powder

Explanation: Black powder produces more smoke and solid residue than modern smokeless propellants, which burn more efficiently.

Question:

A long bullet enters the abdomen almost sideways and produces a broad wound track despite limited deformation. Which projectile behaviour best explains the large surface presented to the tissues?

Options:

Correct Answer: Yaw

Explanation: Yaw is deviation of the bullet’s long axis from its direction of travel, causing a broader surface to strike and disrupt tissue.

Question:

A man is injured by a projectile that first strikes a concrete surface and is deflected before entering his leg. The resulting wound is irregular, and the bullet is flattened. Which term best describes the event before the projectile reached the body?

Options:

Correct Answer: Ricochet

Explanation: Ricochet is deflection after impact with an intermediate surface. It may deform and destabilize the projectile before tissue entry.

Question:

An entry wound has a narrow dark ring immediately inside the abrasion margin. Microscopic examination shows grease, dirt and metallic material transferred from the projectile. What is this finding called?

Options:

Correct Answer: Grease ring

Explanation: The grease or wipe ring is formed when lubricant, dirt and metallic material are wiped from the bullet onto the wound margin.

Question:

A firearm wound lacks soot, scorching and powder stippling. The investigating officer asks the doctor to state the exact muzzle-to-body distance from these findings alone. Which response is most appropriate?

Options:

Correct Answer: Only a distant category can be suggested without test firing

Explanation: Absence of close-range effects supports a distant category, but exact distance requires test firing with comparable weapon and ammunition.

Question:

A military projectile is designed to retain its shape, penetrate deeply and reduce early expansion in soft tissue. Which construction best matches these features?

Options:

Correct Answer: Full metal jacket construction

Explanation: A full metal jacket limits deformation of the lead core, allowing greater shape retention and penetration.

Question:

A circular fibre disc is recovered from a shotgun wound together with pellets. Which function did this component perform before leaving the cartridge?

Options:

Correct Answer: Separated the propellant from the shot charge

Explanation: The wad separates the powder from the pellets and transmits expanding gas pressure to the shot charge.

Question:

Investigators recover a projectile containing a composition that emits visible light during flight, allowing its pathway to be observed in darkness. Which type is this?

Options:

Correct Answer: Tracer bullet

Explanation: A tracer projectile contains a composition that burns visibly during flight, making the trajectory observable.

Question:

A deformed bullet produces an entry defect wider than the projectile’s original calibre. Which statement best explains why the wound diameter cannot be used alone to identify calibre?

Options:

Correct Answer: Projectile behaviour and skin elasticity alter wound size

Explanation: Deformation, angle, yaw and elastic recoil of skin can alter the defect, so wound diameter is not a precise measure of calibre.

Question:

A blast survivor suddenly develops neurological collapse after sustaining severe pulmonary pressure injury. No penetrating cranial trauma is present. Which complication best links the lung injury to the neurological deterioration?

Options:

Correct Answer: Arterial air embolism

Explanation: Blast disruption of lung tissue can introduce air into pulmonary vessels, allowing emboli to reach the cerebral circulation.

Question:

A factory explosion causes no fragment wounds or evidence of body displacement. A worker develops facial burns, smoke inhalation and worsening bronchial disease. Which blast category best includes these effects?

Options:

Correct Answer: Quaternary injury

Explanation: Quaternary effects include burns, smoke or toxic inhalation and exacerbation of pre-existing medical conditions.

Question:

At autopsy after an explosion, a victim has pulmonary contusions, embedded metal fragments, crush fractures and extensive burns. Which interpretation best accounts for this combined pattern?

Options:

Correct Answer: Several blast mechanisms acted on the victim

Explanation: Explosion victims may simultaneously sustain primary, secondary, tertiary and quaternary injuries.

Question:

A patient has a pale, leathery burn extending through the full thickness of the skin. Despite extensive tissue destruction, the centre is less painful than the surrounding area. What best explains this finding?

Options:

Correct Answer: Destruction of sensory nerve endings

Explanation: Full-thickness burns destroy dermal sensory endings, so the deeply burned centre may be relatively painless.

Question:

Hot tea spills onto a child’s clothed thigh. The burn beneath the soaked fabric is deeper than the uncovered splash areas. Which factor most directly produced this difference?

Options:

Correct Answer: Prolonged heat contact from retained fluid

Explanation: Wet clothing holds hot liquid against the skin, increasing contact duration and therefore the depth of thermal damage.

Question:

A burned body has blisters containing protein-rich fluid. The bases of the blisters are red and inflamed. Which interpretation is best supported?

Options:

Correct Answer: The burns developed while circulation was present

Explanation: Protein-rich blister fluid and an inflamed base indicate a vital tissue reaction, supporting antemortem burning.

Question:

During autopsy of a severely charred body, a collection beneath the skull resembles an extradural haemorrhage. There is no corresponding scalp injury or skull impact site. Which interpretation is most appropriate?

Options:

Correct Answer: Heat haematoma

Explanation: Intense heating can produce an intracranial heat haematoma that mimics extradural bleeding without evidence of blunt impact.

Question:

Two workers touch the same faulty electrical appliance. One has dry intact hands, while the other has wet damaged skin and sustains a more severe shock. Which change most directly increased current flow in the second worker?

Options:

Correct Answer: Reduced skin resistance

Explanation: Moist or damaged skin offers less resistance, allowing greater current to pass through the body at the same voltage.

Question:

An electrician develops superficial facial burns when high-voltage electricity jumps across an air gap. There is no evidence that significant current passed through his body. Which injury mechanism is most likely?

Options:

Correct Answer: Flash burn

Explanation: A flash burn results from intense heat generated by an electrical flash, without requiring substantial current passage through the body.

Question:

During a thunderstorm, lightning strikes a tree. A man standing nearby is injured when electricity travels through the soil and enters through his feet. Which mode of lightning exposure occurred?

Options:

Correct Answer: Ground current

Explanation: Ground-current injury occurs when lightning spreads through the earth from a nearby strike and enters the body through points of contact.