Mechanical Engineering Exam  >  Mechanical Engineering Questions  >  A turbine develops 900 kW when running at 200... Start Learning for Free
A turbine develops 900 kW when running at 200 r.p.m. The head on the turbine is 30 m. If the head on the turbine is reduced to 18 m, determine the speed of the turbine (in rpm).
    Correct answer is between '154,155'. Can you explain this answer?
    Most Upvoted Answer
    A turbine develops 900 kW when running at 200 r.p.m. The head on the t...
    Solution:

    Given:

    Power developed by the turbine, P1 = 900 kW

    Speed of the turbine, N1 = 200 rpm

    Head on the turbine, H1 = 30 m

    New head on the turbine, H2 = 18 m

    To find: Speed of the turbine, N2

    Assumptions:

    The turbine is operating under Francis Turbine conditions.

    The change in head does not affect the efficiency of the turbine.

    Formulae:

    The formula to find the power developed by the turbine is given by:

    P = γQH

    Where,

    P is the power developed by the turbine

    γ is the specific weight of the fluid (taken as 9810 N/m3 for water)

    Q is the discharge through the turbine

    H is the head on the turbine

    The specific speed of the turbine is given by:

    N_s = N√Q/H^(3/4)

    Where,

    N is the speed of the turbine

    Q is the discharge through the turbine

    H is the head on the turbine

    Calculation:

    From the given data, we can find the discharge through the turbine for the given power and head as follows:

    P1 = γQ1H1

    900 × 10^3 = 9810 × Q1 × 30

    Q1 = 3.06 m3/s

    Using the specific speed formula, we get:

    N_s1 = N1√(Q1/H1^(3/4))

    200 = N1 √(3.06/30^(3/4))

    N1 = 168.67 rpm

    Now, using the discharge formula, we can find the discharge through the turbine for the new head as follows:

    Q2 = Q1(H2/H1)

    Q2 = 3.06(18/30)

    Q2 = 1.84 m3/s

    Using the specific speed formula, we get:

    N_s2 = N2√(Q2/H2^(3/4))

    N_s2 = N1√(Q2/H2^(3/4))

    N2 = (N_s2/N_s1)² × N1

    N2 = (18/30)^(3/4) × 200

    N2 = 154.3 rpm

    Therefore, the speed of the turbine is 154.3 rpm (rounded to the nearest integer).

    Conclusion:

    The speed of the turbine when the head is reduced from 30 m to 18 m is 154.3 rpm (rounded to the nearest integer).
    Free Test
    Community Answer
    A turbine develops 900 kW when running at 200 r.p.m. The head on the t...
    Explore Courses for Mechanical Engineering exam

    Similar Mechanical Engineering Doubts

    Top Courses for Mechanical Engineering

    A turbine develops 900 kW when running at 200 r.p.m. The head on the turbine is 30 m. If the head on the turbine is reduced to 18 m, determine the speed of the turbine (in rpm).Correct answer is between '154,155'. Can you explain this answer?
    Question Description
    A turbine develops 900 kW when running at 200 r.p.m. The head on the turbine is 30 m. If the head on the turbine is reduced to 18 m, determine the speed of the turbine (in rpm).Correct answer is between '154,155'. Can you explain this answer? for Mechanical Engineering 2025 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about A turbine develops 900 kW when running at 200 r.p.m. The head on the turbine is 30 m. If the head on the turbine is reduced to 18 m, determine the speed of the turbine (in rpm).Correct answer is between '154,155'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2025 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A turbine develops 900 kW when running at 200 r.p.m. The head on the turbine is 30 m. If the head on the turbine is reduced to 18 m, determine the speed of the turbine (in rpm).Correct answer is between '154,155'. Can you explain this answer?.
    Solutions for A turbine develops 900 kW when running at 200 r.p.m. The head on the turbine is 30 m. If the head on the turbine is reduced to 18 m, determine the speed of the turbine (in rpm).Correct answer is between '154,155'. Can you explain this answer? in English & in Hindi are available as part of our courses for Mechanical Engineering. Download more important topics, notes, lectures and mock test series for Mechanical Engineering Exam by signing up for free.
    Here you can find the meaning of A turbine develops 900 kW when running at 200 r.p.m. The head on the turbine is 30 m. If the head on the turbine is reduced to 18 m, determine the speed of the turbine (in rpm).Correct answer is between '154,155'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A turbine develops 900 kW when running at 200 r.p.m. The head on the turbine is 30 m. If the head on the turbine is reduced to 18 m, determine the speed of the turbine (in rpm).Correct answer is between '154,155'. Can you explain this answer?, a detailed solution for A turbine develops 900 kW when running at 200 r.p.m. The head on the turbine is 30 m. If the head on the turbine is reduced to 18 m, determine the speed of the turbine (in rpm).Correct answer is between '154,155'. Can you explain this answer? has been provided alongside types of A turbine develops 900 kW when running at 200 r.p.m. The head on the turbine is 30 m. If the head on the turbine is reduced to 18 m, determine the speed of the turbine (in rpm).Correct answer is between '154,155'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A turbine develops 900 kW when running at 200 r.p.m. The head on the turbine is 30 m. If the head on the turbine is reduced to 18 m, determine the speed of the turbine (in rpm).Correct answer is between '154,155'. Can you explain this answer? tests, examples and also practice Mechanical Engineering tests.
    Explore Courses for Mechanical Engineering exam

    Top Courses for Mechanical Engineering

    Explore Courses
    Signup for Free!
    Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
    10M+ students study on EduRev