Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Work Energy and Power question

2015 · Q135
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /NEET
  3. /Physics
  4. /Work Energy and Power
  5. /2015 · Q135

Work Energy and Power question

2015 · Q135

NEETPhysicsWork Energy and PowerMCQ+4 / −1
The heart of a man pumps 5 litres of blood through the arteries per minute at a pressure of 150 mm of mercury. If the density of mercury be 13.6 ×\times× 103 kg/m3 and g = 10 m/s2 then the power (in watt) is
  1. A
    3.0
  2. B
    1.50
  3. C
    1.70
  4. D
    2.35
View written solutionFree

Correct answer: C

Here, Volume of blood pumped by man’s heart,
V = 5 litres = 5 × 10–3 m3 (∵\because∵ 1 litre = 10–3 m3)

Time in which this volume of blood pumps, t = 1 min = 60 s
Pressure at which the blood pumps,

P = 150 mm of Hg = 0.15 m of Hg
= (0.15 m)(13.6 × 103 kg/m3)(10 m/s2) (∵\because∵ P=hρgP = h\rho gP=hρg)

= 20.4 × 103 N/m2

∴\therefore∴ Power of the heart = PVt{{PV} \over t}tPV​

=(20.4×103N/m2)(5×10−3m3)60 s=1.70 W = {{\left( {20.4 \times {{10}^3}N/{m^2}} \right)\left( {5 \times {{10}^{ - 3}}{m^3}} \right)} \over {60\,s}} = 1.70\,W=60s(20.4×103N/m2)(5×10−3m3)​=1.70W

PreviousNext

More from Work Energy and Power

  • On a frictionless surface, a block of mass M moving at speed v collides elastically with another block of same mass M which is initially at rest. After collision the first block moves at an angle θ to its initial direction and has…2015 · MCQ
  • A block of mass 10 kg, moving in x direction with a constant speed of 10 m s−1, is subjected to a retarding force F = 0.1x J/m during its travel from x = 20 m to 30 m. Its final KE will be2015 · MCQ
  • A particle of mass m is driven by a machine that delivers a constant power k watts. If the particle starts from rest the force on the particle at time t is2015 · MCQ
  • Two similar springs P and Q have spring constants KP and KQ, such that KP > KQ. They are stretched first by the same amount (case a), then by the same force (case b). The work done by the springs WP and WQ are related as, in case (a)…2015 · MCQ
  • A particle with total energy E is moving in a potential energy region U(x). Motion of the particle is restricted to the region when2013 · MCQ
  • One coolie takes 1 minute to raise a suitcase through a height of 2 m but the second coolie takes 30 s to raise the same suitcase to the same height. The powers of two coolies are in the ratio2013 · MCQ
  • A uniform force of (3i+j​) newton acts on a particle of mass 2 kg. Hence the particle is displaced from position (2i+k) metre to position (4i+3j​−k)…2013 · MCQ
  • A car of mass m starts from rest and accelerates so that the instantaneous power delivered to the car has a constant magnitude P0. The instantaneous velocity of this car is proportional to2012 · MCQ