Forensic Ballistics Topicwise Questions || Part-5

Forensic Ballistics Topicwise Questions

Q1. The cutting of barrel length in a shotgun causes?

A) Decrease in dispersion of pellets

B) Increase in dispersion of pellets

C) No change in dispersion in pellets

D) Distortion of pellets

Answer: Increase in dispersion of pellets

Explanation: Cutting of barrel length in shotgun causes increase in dispersion of pellets until the barrel length is reduced to 50% of its typical length.The shotgun has a standard length of 18 inches and smooth bore to reduce friction and barrel of shotgun is made for only specific gauge of ammunition.The barrel walls are thinner due to reduced pressure,shotguns are used for shooting at moving target in air.

Q2. The stamped serial number on the barrel can be restored by?

A) Hydrofluoric acid

B) Ferric chloride reagent

C) Copper chloride reagent

D) Silver chloride reagent

Answer: copper chloride reagent

Explanation: Stamped serial number are made by using a stamp with a positive impression of a number and apply sufficient pressure to impart a negative impression of the stamp of the object.The compressed area at the base of the stamping is strained below the surface of the stamp mark. Copper chloride solution is used in steel/cast iron and the test which is used to detect the stamp serial number on the barrel is Fries reagent.

Q3. Assertion (A): In shotgun, the dispersion of pellets is more in the true cylinder gun than choked gun.

Reason (R): Chocking of barrel is not related to dispersion of pellet.

Codes: A) Both (A) and (R)are correct

            B) (R) is correct, but (A) is incorrect

            C) (A) is correct, but (R) is incorrect

            D) Both (A) and (R) are incorrect

Answer: (A) is correct, but (R) is incorrect

Explanation: Barrel of shotgun are often narrowed down to reduction in the diameter of the barrel near the muzzel end. The purpose is to control the dispersed of the soft charge so that effective range gets increased, hence choking of barrel is related to dispersion of pellet.

Q4. Distance travelled by the firearm discharge in chronological order?

A) Burning,Charring,Blackening,Tattoing

B) Charring,Blackening,Burning,Tattoing

C) Blackening,Charring,Tattoing,Burning

D) Tattoing,Charring,Blackening,Burning

Answer: Charring,Blackening,Burning,Tattoing

Explanation: 

Charring is result of effects of flame or hot gasses produced in the combination of propellants. The charring is caused when the shot is fored from a very close range.Charring can be removed with cotton swab or moistened with spirit.

Blackening is caused by smoke deposition on skin,smoke are light particle they do’not travel far.As the range from the muzzel to target increases the size of zone of powder soot blackening will increase and density decreases.

Tattoing also known as Peppering or stippling it refers to reposition of unburnt or semiburnt powder particle under the skin.Tattoing is an antemortem phenomenon,shows individual was alive at the time he was shot.Lifeless individual have marks of moist gray or yellow, live have reddish brown to orange red color of antemortem.

Q5. Bullet wipe is a term used for

A) Wiping of bullet by hand before firing

B) Wiping of lubricant, soot or other material from bullet on skin of body

C) Cleaning of bullet after fire

D) Sticking of blood on bullet after fire through body

  Answer: Wiping of lubricant,soot or other material from bullet on skin of body

 Explanation: A bullet wipe is a term used in Forensic ballistics which refers to chemical ateration or residue left on the surface of a bullet when it passes through a barrel,used in ballistics tests to help,identify the gun from which the bullet was fired.The discolored area on the periphery of bullet hole,caused by bullet lubricant,lead,smoke,bore debris or jackect material.

Q6. Assertion (A): Test bullet and exhibit bullet can be compared under comparision microscope to establish the identity of a weapon.

Reason (R): Because only firing pin marks on them are identical.

Codes:

A) Both (A) and (R) are true

B) (A) is true but (R) is false

C) Both (A) and (R) are false 

D) (A) is false but (R) is true

 Answer: (A) is true but (R) is false

Explanation: The test bullet and exhibit bullet can be compared under comparision microscope to establish the identity of weapon,as barrel will produce individual markings in addition to bullets land and groove impressions as the bullet passes through,the unique markings determine the given bullet was fired from particular firearm. Whereas,firing pin marks are generated when we pull the trigger a pin like structure hits the percussion cap of catridge.

Q7. ‘Paradox’ gun is a ?

A) Revolver

B) Shotgun

C) Automatic pistol

D) Machine gun

Answer: Shotgun

Explanation: The name ‘paradox’ combines the accuracy and power of a rifel with the lighter weight of a shotgun.Some shotguns have a small portion of their bore near their muzzle end rifled.These are called Paradox guns.

Q8. Percussion lock firearm were discovered by?

A) Friar Bacon

B) Louis

C) James Forsythe

D) Schoenbein

Answer: James Forsythe

Q9. Walker test of GSR is done for the identification of presence of ?

A) Metallic residue

B) Nitrate

C) Sulphur

D) Nitrite

Answer: Nitrite

Explanation: It is used for the detection of nitrite in partially burnt or unburnt propellants. In this technique, a photographic paper is desensitized in hypofixer.Paper is immersed in a solution of 5% of 2 napthylamine-4,8-disulsulphonic acid.Air dried wet 20% acetic acid is placed under the clothing.Photographic paper is palced on the top and covered with a piece of dry cloth.Pressure is applied with a hot iron and set at warm for 5 mins.A bright red spot is observed which confirms the presence of nitrite compounds.

Q10. Fouling is useful in determination of approximate?

A) Distance of fire

B) Time of fire

C) Penetration of projectile

D) Velocity of projectile

Answer: Time of fire

Explanation: Fouling is the dust like burnt powder grains which collect moisture and cause rusting that can be wipped off the body.It is found in close or intermediate shot.Common shot is lead deposition which form grease collar in skin.