Tag: physics

Questions Related to physics

Wedge is a :

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

  1. First order lever

  2. Wheel and-axle

  3. Inclined plane

  4. None of the above

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Correct Option: C

Efficiency of machine is

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

  1. Ratio of velocity of effort to velocity of load

  2. Ratio of the load to its effort

  3. Ratio of useful work done by the machine to the work put to the machine by its effort

  4. All

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Correct Option: C
Explanation:

Mechanical advantage (MA) is the ratio of the load to its effort.
efficiency of machine (n) = MA/VR
Velocity Ratio (VR) is the ratio of the velocity of effort to velocity of load.

Relationship between the mechanical advantage and velocity ratio of an ideal machine is

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

  1. Velocity Ratio < mechanical advantage

  2. Velocity Ratio = Mechanical advantage

  3. Velocity ratio > Mechanical advantage

  4. All

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Correct Option: B
Explanation:

For ideal machine, efficiency = 1

effeciency = Mechanical advantage/ velocity ratio
So, for ideal machine, Mechanical advantage = velocity ratio

Relationship between mechanical advantage and velocity ratio for a practical machine is

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

  1. Velocity ratio = Mechanical advantage

  2. Velocity ratio > Mechanical advantage

  3. Velocity ratio < mechanical advantage

  4. All

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Correct Option: B
Explanation:

For a practical machine, velocity ratio is greater than mechanical advantage
V.R > M.A.

The ratio of the load to the effort is called.

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

  1. Mechanical advantage

  2. Velocity ratio

  3. Efficiency of machine

  4. None

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Correct Option: A
Explanation:

Ratio of load to the effort is k/a mechanical advantage of the machine. The ratio of the velocity of effort to its velocity of the load is called its velocity ratio of machine.

Ratio of velocity of effort to the velocity of load is called.

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

  1. Mechanical advantage

  2. Velocity ratio

  3. Efficiency of machine

  4. None

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Correct Option: B
Explanation:

Ratio of the velocity of effort to the velocity of load is called velocity ratio of machine. Ratio of the load to its effort is called mechanical advantage of 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 = $5cm = .05m$
$Effort (P) = 10N$
$n(Efficiency) = 50\%$
$MA = Load/Effort = W/P=200N/10N=20$