In a lifting machine with efficiency 60%, an effort of 200 N is required to raise a load of 6 kN. The velocity ratio of the machine is_____________________?

Related Mcqs:

1. In a lifting machine a weight of 5 kN is lifted through 200 mm by an effort of 0.1 kN moving through 15 m. The mechanical advantage and velocity ratio of the machine are respectively_____________________?

   A. 50 and 75
   B. 75 and 50
   C. 75 and 75
   D. 50 and 50

2. The condilion for a lifting machine to be reversible is that its efficiency should be_________________?

   A. less than 50%
   B. more than 50%
   C. more than 66.67%
   D. equal to 100%

3. A hoop of radius 3 m weighs 100 kg. It rolls along a horizontal floor so that at its centre of mass has a speed of 200 mm/sec, . The work required to stop the hoop is______________?

   A. 2 J
   B. 4 J
   C. 6 J
   D. 8 J

4. A rope is wrapped twice around a rough pole with a coefficient of friction ‘A . It is subjected to a force Fj at one end and a gradually increasing force F2 is applied at the other end till the rope just starts slip-ping. At this instant the ratio of F2 to Fi is_____________________?

   A. 1
   B. e2*
   C. e4*
   D. e*72

5. The total kinetic energy of a hoop of mass 2 kg and radius 4 m sliding with linear velocity 8 m/sec and angular velocity 5 radian/sec is_________________?

   A. 64 J
   B. 400 J
   C. 464 J
   D. 89 J

6. If a projectile is fired with an initial velocity of 10 m/sec at an angle of 60° to the horizontal, its horizontal and vertical velocity at the highest point of trajectory are___________________?

   A. 0 and 5 m/sec
   B. 5 m/sec and 0
   C. 5 V3 m/sec and 0
   D. 5 and 5V3 m/sec

7. A stone was thrown vertically upwards from the ground with a velocity of 50 m/sec. After 5 seconds another stone was thrown vertically upwards from the same place. If both the stones strike the ground at the same time, then the velocity with which the second stone was thrown should be (Assume g = 10 m/sec2)______________________?

   A. 15 m/sec
   B. 25 m/sec
   C. 40 m/sec
   D. 50 m/sec

8. A shell travelling with a horizontal velocity of 100 m/sec explodes and splits into two parts, one of mass 10 kg and the other of 15 kg. The 15 kg mass drops vertically downward with initial velocity of 100 m/sec and the 10 kg mass begins to travel at an angle to the horizontal of tan”1 x, where x is______________________?

   A. 3/4
   B. 4/5
   C. 5/3
   D. 3/5

9. If a flywheel increases its speed from 10 rpm to 20 rpm in 10 seconds, then its angular acceleration is_____________________?

   A. —rad/sec 10
   B. —rad/sec 20
   C. —rad/sec 30
   D. none of the above

10. A symmetrical body is rotating about its axis of symmetry, its moment of inertia about the axis of rotation being 2 kg -m2 and its rate of rotation 2 revolutions/see. The angular momentum of the body in kg-m2/sec is_____________________?

    A. 4
    B. 6 7i
    C. 8TC
    D. 8