Which instrument is used to measure the blood pressure manually ?
- A.Sphygmomanometer
- B.Centrifuge
- C.Electrophoresis
- D.Thermal cycler
Correct answer
Explanation
The correct answer is A, Sphygmomanometer. A sphygmomanometer has an inflatable cuff wrapped around the upper arm, a rubber bulb to pump air into it, and a gauge, traditionally a column of mercury. The cuff is inflated until it stops blood flow in the brachial artery and is then slowly released while the doctor listens with a stethoscope. The pressure at which the first tapping sound is heard is the systolic pressure, and the pressure at which the sound disappears is the diastolic pressure. Blood pressure is written as systolic over diastolic in millimetres of mercury, about 120/80 mmHg for a healthy adult. The instrument was developed by Samuel von Basch in 1881 and improved by Scipione Riva-Rocci in 1896. Option B is wrong because a centrifuge spins samples to separate parts of different density, such as plasma from blood cells. Option C is wrong because electrophoresis separates DNA or proteins in an electric field. Option D is wrong because a thermal cycler runs the heating cycles of PCR. Exam tip: sphygmomanometer for blood pressure, normal about 120/80 mmHg.
Practice Questions
View allWho among the following built a model steam engine in 1698 called "Miner's Friend" to drain mines ?
- A.Thomas Savery
- B.Thomas Newcomen
- C.James Watt
- D.Richard Arkwright
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The English engineer Thomas Savery patented a steam pump in 1698 and called it the Miner's Friend, as it was meant to pump water out of flooded mines.
Read the full explanation →A metallic wire having resistance of 20 Ω is cut into two equal parts in length. These parts are then connected in parallel. The resistance of this parallel combination is equal to
- A.20 Ω
- B.10 Ω
- C.5 Ω
- D.15 Ω
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Each half of the wire has a resistance of 10 Ω, and two 10 Ω resistors in parallel give 5 Ω. The resistance of a wire is R = ρL/A, so it is directly proportional to its length when the material and thickness stay the same.
Read the full explanation →Myopia is a defect in human vision where an image of a
- A.nearby object is focused beyond the retina.
- B.nearby object is focused before the retina.
- C.distant object is focused before the retina.
- D.distant object is focused beyond the retina.
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In myopia, or short-sightedness, a person sees near objects clearly but distant objects look blurred because their image forms in front of the retina.
Read the full explanation →A homogeneous mixture contains two liquids. How are they separated ?
- A.By filtration
- B.By evaporation
- C.By distillation
- D.By condensation
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Two miscible liquids that form a homogeneous mixture are separated by distillation, which uses the difference in their boiling points.
Read the full explanation →Cartilage is NOT found in
- A.larynx
- B.nose
- C.ear
- D.urinary bladder
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The urinary bladder is a hollow muscular sac made of smooth muscle and a stretchable lining; it has no cartilage.
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