Tag: simple machine

Questions Related to simple machine

It is difficult to climb the steps having greater inclination. Why?

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

  1. Less erect steps require less energy

  2. Greater inclination requires less effort because of the high mechanical advantage

  3. Greater inclination requires more effort because of the low mechanical advantage

  4. None of the above

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Correct Option: C

Velocity Ratio of a machine is more than 1. It 

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

  1. Acts as a force multiplier

  2. Gives loss of speed

  3. A and B

  4. Either A or B

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Correct Option: C
Explanation:

VR = Velocity of effort / velocity of load

VR > 1 means velocity of effort is more than load, hence loss of speed
VR > 1 then machine acts as a force multiplier

A force of 10N raised a load of 400 kg. Calculate mechanical advantage of the machine.

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

  1. 50

  2. 400

  3. 10

  4. 4000

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Correct Option: B
Explanation:

Mass given $= 400\  kg$


Effort $= 10\ N$

$MA = \dfrac{load}{effort} = \dfrac{4000}{10} = 400$.

A machine is used to displace a load of $200$ N through $5$ cm by an effort of $10$ N. If efficiency of the machine is $50\%$. Find its mechanical equivalent.

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

  1. 5

  2. 20

  3. 10

  4. 2

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Correct Option: B
Explanation:

Load = $w = 200N$
Distance moved by the load = $5cm = .05m$
$Effort (P) = 10N$
$n(Efficiency) = 50\%$
$MA = Load/Effort = W/P=200N/10N=20$

A pulley system of VR of 2 and efficiency of 50%. If the effort moves through a distance of 5m. Calculate the distance moved by the load.

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

  1. 2m

  2. 5.6m

  3. 10m

  4. 2.5m

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Correct Option: D
Explanation:

Given:  $VR=2$


From the relation $VR=\dfrac{\text{Distance moved by effort}}{\text{distance moved by load}}$


Using formula we get distance moved by the load is $2.5m$

........ is defined as the ratio of the distance moved by effort and load, in the same time interval.

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

  1. Velocity ratio

  2. Mechanical advantage

  3. Both

  4. None

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Correct Option: A
Explanation:

Velocity ratio = $\displaystyle \frac { Distance\quad moved\quad by\quad the\quad effort }{ Corresponding\quad distane\quad moved\quad by\quad the\quad load } $
It only depends on the design of machine and is always same for a particular machine.

Efficiency is

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

  1. $\displaystyle \frac { Energy\quad input }{ Energy\quad output } \times 100$

  2. $\displaystyle \frac { mechanical\quad advantage }{ velocity\quad ratio } \times 100$

  3. Both

  4. None

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Correct Option: C
Explanation:

As no machine is perfectly efficient.
So, we define efficiency as efficiency = $\displaystyle \frac { Energy\quad input }{ Energy\quad output } \times 100$
Also Efficiency = $\displaystyle \frac { mechanical\quad advantage }{ velocity\quad ratio } \times 100$
A petrol engine is about 30% efficient, a diesel engine is 40% efficient.

A machine in which displacement of load is more than the displacement of effort, will have the velocity ratio

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

  1. More than 1

  2. Less than 1

  3. Equal to 1

  4. All

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Correct Option: B
Explanation:

A machine in which displacement of load is more than the displacement of effort, will have the velocity ratio more than 1.

Friction has no effect on 

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

  1. Velocity Ratio

  2. Mechanical Advantage

  3. Efficiency

  4. All of the above

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Correct Option: A
Explanation:

Friction has effect on Mechanical Advantage and efficiency but not Voltage Ratio.

Effeciency of inclined plane

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

  1. Zero

  2. One

  3. Two

  4. Three

Show answer
Correct Option: B
Explanation:

$\eta=\frac{M.A}{V.R}=\frac{l}{h(l/h)}=1$
$M.A=\frac{l}{h}, V.R=\frac{l}{h}$