Tag: common machines

Questions Related to common machines

The helical threading of a screw :

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. increases the mechanical advantage

  2. helps to gain less inclination

  3. holds the wood more firmly than a screw

  4. all of the above

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Correct Option: D
Explanation:
 A small torque applied to a screw  can exert a large axial force on a mass. Therefore, a threaded  component is said to produce a Mechanical Advantage.

(a) Helical threading increases the mechanical advantage.
(b) Also provide less inclination whenever heavy load  act on it.
(c) Helical threading means increasing pitch so it holds wood more firmly than a screw.

A wedge is:

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. a first order lever

  2. a wheel-and-axle

  3. two inclined planes put together

  4. none of the above

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Correct Option: C
Explanation:

A wedge can be made by putting two inclined plane together .

A screw is preferred over a nail to insert into wood because :

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. Screw holds more firmly than a nail.

  2. Less force is needed to insert a screw.

  3. Tip of a screw has more area of contact than nail.

  4. Fulcrum of the screw is at its head.

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Correct Option: A,B,D
Explanation:

(a) Screw has thread like grip on it so it holds more firmly than a nail.

(b) You have apply  to torque to insert screw which require less force on the other hand nail require huge impulse to insert.
(c) Tip of both has approximately equal area.
(d) Fulcrum is a pivot around a lever turns ,or something that plays a central role. screw has it at its head.

State true or false.
The more gradual the slope of an inclined plane, then more effort is required to push a load up.

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. True

  2. False

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Correct Option: A
Explanation:

As slope increases component of weight along inclined plane increases so more effort required to push a load up.

A car develops a force of 400 N and climbs up a vertical distance of 250 m. If the length of the road covered by the car is 5 km, then find the fractional change in load due to the car for the force developed.

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. 19

  2. 20

  3. 21

  4. 22

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Correct Option: A
Explanation:

$ MA = \displaystyle \frac{L _{car}}{E _{car}} = \frac{EA}{LA}$
$\displaystyle \frac{L _{car}}{400} = \frac{5000}{250}$
$L _{car} = 8000 N$
Fractional change
$= \displaystyle \frac{L _{car}-E}{E}$
$= \displaystyle \frac{8000 - 400}{400}$
$= \displaystyle \frac{7600}{400}$
$=19$

Screw is a/an

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. lever

  2. gear

  3. inclined plane

  4. wheel

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Correct Option: C
Explanation:

A screw is a modification of an inclined plane . The threads of a screw are like an inclined plane wrapped around a cylinder.

As the inclination of the screw increases, the distance between the threads

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. increases

  2. decreases

  3. remains the same

  4. may increase or decrease

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Correct Option: B

If the threads of a screw are closer:

physics common machines kinds of simple machines inclined plane, wedge, screw and wheel and axle types of simple machines

  1. mechanical advantage decreases

  2. inclination increases

  3. effort required will be less

  4. all the above

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Correct Option: C
Explanation:

If threads of a screw are closer then inclination decreases so it has became easy to drive screw or effort required will be less.

A pulley system has a single fixed pulley and a single movable pulley. Its mechanical advantage is ____ .

physics a little effort, lot of work motion in application common machines introduction to simple machines

  1. 1

  2. 2

  3. 3

  4. 4

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Correct Option: B

A simple machine :

physics a little effort, lot of work motion in application common machines introduction to simple machines

  1. magnifies the movement only

  2. enables to do more work by less effort

  3. changes the direction of force in all circumstances

  4. none of the above

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Correct Option: B