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
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
Answer & ExplanationAnswer: D) Rolling friction is much more than sliding friction, the use of ball bearings in a machine considerably reduces friction
‘Rather’ is always followed by ‘Than’. Thus, the phrase ‘would rather have’ is grammatically correct. The correct formation would be, ‘I would rather have a noble enemy than a mean friend’.
In IF7 out of 7 Flourine atoms 5 of them are placed on a plane in Pentagon shape .In remaining 2 flourines one is placed above the plane and other below the plane each at 90 degrees