10th ICSE PHY MACHINES

Which of the statement is not true for a machine ?

• It can multiply force

• It can increase speed

• It can change the direction of applied force.

• Its output can be more than input.

Which of the statement is not true for an actual machine?

• Its mechanical advantage is less than velocity ratio

• Its efficiency is always less than 100%

• Its mechanical advantage is greater than velocity ratio.

• Output of machine is always less than input

A lever which always has mechanical advantage less than 1 has :

• Load between effort and the fulcrum.

• Effort between the load and the fulcrum.

• Fulcrum between the load and effort.

• Effort and load act at same point.

The correct relationship between the effort (E) load (L) and mechanical advantage (M.A.) is : (a) (b (c)(d)

• M.A. = L × E

• ) M.A. × E = L

• M.A. x L= E

• none of these

The correct relationship between the velocity ratio (V.R) the distance through which effort act (d) and the distance through which load moves (D)

• V.R. × D = d

• V.R. = D × d

• V.R. × d = D

• none of these

The correct relationship between the efficiency (η), mechanical advantage (M.A.) and velocity ratio (V.R.) of an actual machine is : (a) (b) . (c) (d) both (b) and (c)

• η = M.A × V.R

• η = M.A. ÷ V.R

• η × V.R. = M.A.

• η × V.R. = M.A.

A fire tong is a lever of

• First order

• Second order

• Third order

• none of these

. A person standing vertically upon his toes is an example of lever of

• First order

• Second order

• Third order

• none of these

A lever which always have mechanical advantage more than 1 is

• Lever of first order

• Lever of second order

• Lever of third order

• none of these

. A lever which can have mechanical advantage either less than one or more than one depending upon the position of fulcrum is a lever of :

• First order

• Second order

• Third order

• none of these