TORQUE 119
- The unit of power is:
(a) N (b) J (c) W (d) N/m
- The unit of the moment of inertia is:
(a) kg m^2 (b) kg
(c) kg/m^2 (d) N m
- A force of 100 N is applied to the rim
of a pulley wheel of diameter 200 mm.
The torque is:
(a) 2 N m (b) 20 kN m
(c) 10 N m (d) 20 N m
- The work done on a shaft to turn it
through 5πradiansis25πJ. The torque
applied to the shaft is:
(a) 0.2 N m (b) 125π^2 Nm
(c) 30πNm (d)5Nm
- A 5 kW electric motor is turning at
50 rad/s. The torque developed at this
speed is:
(a) 100 N m (b) 250 N m
(c) 0.01 N m (d) 0.1 N m
- The force applied tangentially to a bar
of a screw-jack at a radius of 500 mm if
the torque required is 1 kN m is:
(a) 2 N (b) 2 kN
(c) 500 N (d) 0.5 N
- A 10 kW motor developing a torque
of (200/π) N m is running at a speed
of:
(a) (π/20) rev/s (b) 50πrev/s
(c) 25 rev/s (d) (20/π)rev/s
- A shaft and its associated rotating parts
has a moment of inertia of 50 kg m^2.
The angular acceleration of the shaft
to produce an accelerating torque of
5kNmis:
(a) 10 rad/s^2 (b) 250 rad/s^2
(c) 0.01 rad/s^2 (d) 100 rad/s^2
- A motor has an efficiency of 25%
when running at 3000 rev/min. If the
output torque is 10 N m, the power
input is:
(a) 4πkW (b) 0. 25 πkW
(c) 15πkW (d) 75πkW
- In a belt-pulley wheel system, the
effective tension in the belt is 500 N
and the diameter of the driver wheel is
200 mm. If the power output from the
driving motor is 5 kW, the driver pulley
wheel turns at:
(a) 50 rad/s (b) 2500 rad/s
(c) 100 rad/s (d) 0.1 rad/s
