Related Questions

Which of the following is NOT true about Frictional force? A. Friction is the force which opposes the relative motion of two surfaces in contact. B. The force of friction that acts when a body is moving (sliding) on a surface is called sliding friction. C. Friction in machines wastes energy and also causes wear and tear. D. Rolling friction is much more than sliding friction, the use of ball bearings in a machine considerably reduces friction.
Consider the following statements: 1. The kinetic friction is always less than the rolling friction. 2. The kinetic friction is always equal to the rolling friction. 3. The kinetic friction is always greater than the rolling friction. Which of the following statement is correct?
While discussing about friction, a teacher gave a number of examples to explain the concept. Some of the examples where friction is useful in our day-to-day life as quoted by the teacher are given below : A. We are able to write because of friction between the tip of the pen and the paper. B. We are able to walk because of friction between our feet and the ground. C. A ball thrown vertically upwards comes back to us due to friction. D. We are able to stop a moving vehicle by applying brakes because of friction. The correct examples were
Name the duct formed when the cystic duct joins with hepatic duct.
Air at atmospheric pressure and 20 degree Celsius flows with 6 m/s velocity through main trunck duct of air conditioning system. The duct is rectangular in cross-section and measures 40 cm by 80 cm. Determine heat loss per meter length of duct corresponding to unit temperature difference. The relevant thermos-physical properties of air are v = 15 * 10 -6 m 2/s α = 7.7 * 10 -2 m2/hr k = 0.026 W/m degree
Which of the following statements regarding laws governing the friction between dry surfaces are correct? 1. The friction force is dependent on the velocity of sliding.  2. The friction force is directly proportional to the normal force. 3. The friction force is dependent on the materials of the contact surfaces. 4. The Friction force is independent of the area of contact surfaces.
Air at a density of 1.2 kg/m3 flows in a straight duct such that the velocity at the centre is 12.5 m/s. the method factor for the velocity profile is known to be 0.80. The air flow encounters a symmetric expansion such that the cross- sectional are of the duct becomes double. The static pressure value at the inlet and outlet of the expansion are 60 Pa and 90 Pa respectively. Neglecting friction the shock pressure loss on account of expansion in Pa is
Which of the following is correct about friction? I. Rolling friction is smaller than the sliding friction II. Sliding friction is smaller than static friction 
A post tensioned cable of beam 10m long is initially tensioned to a stress of 1000n/mm2 at one end, slope is 1 in 24 tendons curved at each end , area is 600mm2, Es is 210kn/mm2, coefficient of friction between duct and cable is 0.55, friction coefficient for wave effect is 0.0015perm. During anchorage, if there is a slip 3mm at the jacking end, calculate final force?
Group I shows different heat addition processes in power cycles. Likewise, Group II shows different heat removal processes. Group III lists power cycles. Match items from Groups I, II and III. Group I Group II Group III P. Pressure constant S. Pressure constant 1. Rankine cycle Q. Volume constant T. Volume constant 2. Otto cycle R. Temperature constant U. Temperature constant 3. Carnot cycle     4. Diesel cycle     5. Brayton cycle