Tag: terms related to machines

Questions Related to terms related to machines

Akhil has to lift a load of 800 N onto a platform of 2 m height. Instead, he pushes the load up a ramp 4 m long. Find the force required to roll the load up the ramp.

physics lever common machines terms related to machines introduction to simple machines

  1. 200 N

  2. 600 N

  3. 400 N

  4. 800 N

Show answer
Correct Option: C
Explanation:

Force required to roll the load up the ramp (F) $=\displaystyle \frac{load \times height}{distance}$
$= 800 \displaystyle \times \frac{2}{4} = 400 N$

The ratio of the radius of two wheels A and B are in the ratio 3 : 7 respectively and the ratio of their respective axles is 5 : 4. Identify the wheel and axle that has greater mechanical advantage?

physics lever common machines terms related to machines introduction to simple machines

  1. A

  2. B

  3. Both have same

  4. Can't say

Show answer
Correct Option: B
Explanation:

The mechanical advantage of a wheel and axle $= \displaystyle \frac{Radius \ of \ wheel}{Radius \ of \ the \ axle}$
$MA _A = \displaystyle \frac{R _1}{r _1} $ and  $MA _B = \displaystyle \frac{R _2}{r _2}$
Given $ r _1  :  r _2  = 5 : 4$
$R _1  :  R _2  = 3  :  7$
$ \displaystyle \frac{MA _A}{MA _B} = \frac{R _1}{r _1} \times \frac{r _2}{R _2}$
$\displaystyle = \frac{3}{5} \times \frac{4}{7} = \frac{12}{35}$
$MA _B >  MA _A$

In a wheel-axle arrangement, the radius of wheel is 25 times more than the radius of an axle. Find the mechanical advantage of the machine.

physics lever common machines terms related to machines introduction to simple machines

  1. 20

  2. 25

  3. 30

  4. 35

Show answer
Correct Option: B
Explanation:

The mechanical advantage of a wheel and axle $= \displaystyle \frac{Radius  of  wheel}{Radius  of  the  axle}$
Given radius of wheel $=$ 25 $\times$ radius of axle
$MA = \displaystyle \frac{25 \times radius  of  axle}{radius  of  axle} = 25$

Which of the following statements in NOT correct?

physics lever common machines terms related to machines introduction to simple machines

  1. In a first order lever, the fulcrum is placed between the effort and the load.

  2. The mechanical advantage of a second class levers is greater than 1 as load is situated in between to effort and fulcrum.

  3. An inclined plane in a hospital, helps in pushing a wheel chair easily.

  4. A crow bar is an example of second class level.

Show answer
Correct Option: A,B,C

An effort of 20 kgf is applied on a machine through a distance of 80 cm, when a load of 30 kgf moves through a distance of 1 cm. Calculate the velocity ratio of the machine.

physics lever common machines terms related to machines introduction to simple machines

  1. 40

  2. 80

  3. 160

  4. 60

Show answer
Correct Option: B
Explanation:

Velocity ratio $= \displaystyle \frac{distance \ of \ the \ effort}{distance \ moved \ by \ the \ load}$
$= \displaystyle \frac{80  cm}{1  cm}= 80$

Akhil has to lift a load of 800 N onto a platform of 2 m height. Instead, he pushes the load up a ramp 4 m long. Find the work done by Akhil in lifting the load vertically up.

physics lever common machines terms related to machines introduction to simple machines

  1. 800 J

  2. 1600 J

  3. 400 J

  4. 200 J

Show answer
Correct Option: B
Explanation:

The work done by Akhil in lifting the load vertically up $=$ Force $\times$ height
$= 800 \times 2 = 1600 \ J$

A crow-bar of length $2.0$ m is used as a machine to lift a box of $100$ kgf by placing a fulcrum at a distance of $0.1$ m from the box. Calculate the effort required.

physics lever common machines terms related to machines introduction to simple machines

  1. 1.9 m

  2. 19 m

  3. 29 m

  4. 30 m

Show answer
Correct Option: A

A nut can be opened by a lever of length $0.25$ m by applying a force of $80$ N. What should be the length of the lever if a force of $32$ N is enough to open the nut?

physics lever common machines terms related to machines introduction to simple machines

  1. $625$ m

  2. $1625$ m

  3. $0.625$ m

  4. $6.25$ m

Show answer
Correct Option: C

A rubber ball dropped from a height of $20\ m (g = 10\ m/s^{2})$ falls on the roof of an elevator going up at $2\ m/s$. If the collision of the ball with the elevator is elastic, the ball rebounds with a velocity of

physics lever common machines terms related to machines introduction to simple machines

  1. $20\ m/s$

  2. $22\ m/s$

  3. $24\ m/s$

  4. $26\ m/s$

Show answer
Correct Option: C

Efficiency of engine is $\eta _1$ at $T _1 = 200^\circ C$ and $T _2 = 0^\circ C$ and $\eta _2$ at $T _1 = 0^\circ C$ and $T _2 = -200 K$. Find the ratio of $\dfrac{\eta _1}{\eta _2}$.

physics lever common machines terms related to machines introduction to simple machines

  1. $1.00$

  2. $0.577$

  3. $0.721$

  4. $0.34$

Show answer
Correct Option: C