Tag: physics

Questions Related to physics

Which of the following is not true of the standard weights and Measures? 

physics measurements and units measuring mass measurement of mass measuring instruments

  1. Larger weights are made of iron

  2. Smaller weights are made of lead

  3. The value is written on the top

  4. They are either hexagonal or circular in shape

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Correct Option: C

What principle is used In a  newton spring balance?

physics measurements and units measuring mass measurement of mass measuring instruments

  1. The mass of an object depends on its density.

  2. The mass of an object depends an the gravity pulling

  3. The weight of an object is directly proportional to its mass.

  4. The extension of the spring is directly proportional to the force pulling it.

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Correct Option: D

Which of the following principle helps in the measurement of mass of the planets?

physics measurements and units measuring mass measurement of mass measuring instruments

  1. Einstein's theory of relativity

  2. Newton's Law of gravitation

  3. Newton's Law of cooling

  4. Parallax Method

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Correct Option: B
Explanation:

With the help of Newton's law of gravitation we can measure mass of planets.

Newton's law of universal gravitation states that a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

$F=\dfrac { G{ m } _{ 1 }{ m } _{ 2 } }{ { r }^{ 2 } } $   where $m _1$ amd $m _2$ are mass of planets, and $r$ is the distance between them  and $G$ is gravitation constant.
From this we can measure mass of planets.

A body is attached to a spring balance suspended from a stand. The reading on the balance is $0.5$kg. The two together are detached from the stand and allowed to fall through a height. While falling the reading in the balance will be.

physics measurements and units measuring mass measurement of mass measuring instruments

  1. More than $0.5$ kg depending on the height

  2. Less than $0.5$ kg but not zero

  3. Zero

  4. $0.5$ kg

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Correct Option: C

We can measure weights using both spring and beam balance. But on moon, which one will give accurate measuring ?

physics measurements and units measuring mass measurement of mass measuring instruments

  1. Beam Balance

  2. Spring Balance

  3. Both

  4. None

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Correct Option: A
Explanation:

Spring balance is used to measure the weight of the body whereas beam balance is used to measure the mass of the body. Since the mass of the body remains the same on earth as well as on moon but the acceleration due to gravity differs. So, the beam balance gives the same value of mass of body on earth and moon but spring balance gives different values of weight. So we can measure the mass of body on moon by beam balance and then multiply it by $g = 9.8 \ m/s^2$ to get the weight which would be more accurate.

What will be the reading of spring balance if a block of mass 5kg is hung to it ? 
(Take g =10 $m/s^2$)

physics measurements and units measuring mass measurement of mass measuring instruments

  1. $35 N$

  2. $40 N$

  3. $50 N$

  4. $60 N$

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Correct Option: C
Explanation:

Mass of the block   $m = 5 \ kg$
Given : $g = 10 \ m/s^2$
Thus reading of spring balance  $W = mg = 5\times 10  =50 \ N$

An object is suspended from a spring balance in a lift. The reading is $240 N$ when the lift is at rest. If the spring balance reading now changes to $220 N$, the the lift is moving 

physics measurements and units measuring mass measurement of mass measuring instruments

  1. Downward with constant speed

  2. Downward with decreasing speed

  3. Downward with increasing speed

  4. Upward with increasing speed

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Correct Option: C
Explanation:
Since the apparent weight of the body decreases, the lift should move downward with some acceleration.

A body is suspended from a spring balance kept in a satellite . The reading of the balance is ${ W } _{ 1 }$ when the satellite goes in an orbit of radius R and is ${ W } _{ 2 }$ when it goes in an orbit of radius 2 R. 

physics measurements and units measuring mass measurement of mass measuring instruments

  1. ${ W } _{ 1 }$ = ${ W } _{ 2 }$

  2. ${ W } _{ 1 }$ < ${ W } _{ 2 }$

  3. ${ W } _{ 1 }$ > ${ W } _{ 2 }$

  4. ${ W } _{ 1 }$ $\neq $ ${ W } _{ 2 }$

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Correct Option: A

A monkey is sitting in the pan of a spring balance kept in an elevator. The reading of the spring balance is maximum when the elevator.

physics measurements and units measuring mass measurement of mass measuring instruments

  1. Is in stationary

  2. Accelerate upwards

  3. Falls freely

  4. Accelerate Downwards

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Correct Option: A

Ebonite handles are used to handle hot utensil because they are bad conductors of heat.

physics temperature and heat modes of heat transfer - conduction conduction heat and modes of heat transfer

  1. True

  2. False

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Correct Option: A
Explanation:

Yes, it's true that ebonite are bad conductors of heat so they are used to handle hot utensis.