Measuring Mass - class-XI
measuring mass,physical quantities and measurement, nature of the physical world and ,measuring instrument, measurements and units,forces and motion.
Questions
In a physical balance, when the beam is released with empty pans, the successive left and right turning points are obtained as 5; 6, 6 and 18, 18 respectively. After placing the substance whose mass is to be determined and when beam is released, the resting point obtained is 13. When 10 mg is added to the pan, the resting point is obtained as 11. If the mass at LRP is 60 g, the correct mass of the body corrected to a milligram is ______ g.
- 59.996
- 56.5
- 59.99
- 56.599
State whether true or false.
The pointer of a spring balance will read zero when there is no load on the pan.
- True
- False
The weight placed on the pan is a balance when HRP is obtained is 47.86 g. The difference between ZRP and HRP of the physical balance is 3. When 10 mg is added in its pan, the difference between HRP and LRP is obtained as 5. Determine the most accurate mass of the body.
- 478.672 g
- 34.73 g
- 47.866 g
- 47.532 g
A beam balance is used to measure the ________ of a body.
- weight
- mass
- force
- shape
A knob at the baseboard can be used to raise or lower the _____of the physical balance
- beam
- weight
- mass
- none
A spring balance gives the measure of the mass of a body. True or false.
- True
- False
Point out the odd one out of the following
beam balance, spring balance, physical balance
- Spring balance
- Beam Balance
- Physical Balance
- None
Name a common device, among the following, used to measure the weight of a body.
- Spring balance
- Beam balance
- Rheostat
- Potentiometer
Name a common device, among the following, used to measure mass of a body.
- Physical balance
- Spring balance
- Barometer
- Speedometer
Select the odd one out (mass, beam balance, kilogram, spring balance)
- beam balance
- mass
- spring balance
- kilogram
weight can be found by using a physical balance
- True
- False
Mass is found by using a beam/spring balance.
- True
- False
State whether true or false.
Physical balance is used to measure the weight of a body.
- True
- False
A simple balance can measure small masses accurately.
- True
- False
Before using the beam balance why is the beam raised gently by raising the platform?
- To make one side of the beam balance heavy
- To ensure that the pointer swings equally on both sides of the zero mark on scale
- Both
- None
The beam should be _________ each time before adding or removing weights from the pan.
- raised
- lowered
- Both
- None
Which of the following is a correct about precautions to be taken while using beam balance?
- The weights should be carried with foreceps
- They should not be carried with bare fingers to avoid the change in its weight due to the presence of moisture and dust particles
- Wet and hot objects should not be kept on the pan
- All of the above
Which of the following is not correct precaution taken while using beam balance?
- When near the actual weight, the weights should always be tried in the descending order
- The beam should be lowered each time before adding or removing weights from the pan
- The weights should be replaced into the weight box after weighting
- None
Which of the following is/are correct condition(s) for a True Balance?
- Both arms must be of equal lengths
- Both pans must be of equal weights
- Both A and B
- None of A and B
The weights should be tried in descending order, for a beam balance, when we are :
- near the actual weight
- far from the actual weight
- measuring any weight as a constant practice
- making a rough estimation of the actual weight
Identify the correct statement for measuring weight using a beam balance:
- When near the actual weight, weights should be tried in decreasing order
- The beam should be lowered before adding or removing weights from the pan
- Both A and B are true
- Neither A nor B is true
Identify the wrong way of handling a beam balance:
- The lever should be turned fast in order to prevent the knife edges from chipping
- The weight should be replaced into the weight box after weighing
- Wet and hot objects should not be kept on the plan
- When near the actual weight ,weights should be tried in decreasing order
While using a beam balance, if we do not turn the lever gently,
- the knife edges will be chipped
- the lever will break
- the beam will break
- nothing will happen
Wet objects should not be kept on the pan as :
- the weight measured will be more than actual
- the weight measured will be less than actual
- the weight measured will be same as actual
- the pan may break down
The weights in a beam balance should not be carried with bare fingers
- to avoid change in weight due to moisture and dust
- to avoid change in weight due to chemical reactions
- just to make use of the forceps
- to avoid dropping of weights on the pan
Fill in the blank:
In a beam balance, the beam should be ______ before adding or removing weights from the pan.
- raised
- lowered
- held horizontal
- held vertical
Mark the correct statement regarding to beam balance.
- The physical balance consists of a light and rigid beam of brass, a metallic pillar, a wooden base, two pans, a metallic pointer, and an ivory scale
- The device is enclosed in a box to avoid the effect of wind
- A weight box containing standard weights comes with the balance
- All of the above
When we are near to getting the actual weight in a beam balance, standard weights should be tried in :
- decreasing order
- increasing order
- either increasing or decreasing order
- at random
Objects measured in beam balance should be
- hot and wet
- hot but not wet
- wet but not hot
- neither hot nor wet
An object is weighed in the following places using a spring balance. In which place will it weigh the heaviest?
- On the Moon
- At the equator
- At the pole
- In outer space
Which of the following devices are used for the measurement of mass?
- Simple pendulum
- Beam balance
- Electroscope
- Microscope
Burette and Pipette are used to measure mass
- True
- False
Which of the following should not be weighed directly in contact with a balance pan?
- glass
- ceramics
- laboratory chemicals
- metal objects
Which of the following is not conducive to an accurate measurement of mass on a beam balance?
- Isolated surroundings
- Still air
- Air currents
- None of these
The weights should be carried with forceps to :
- avoid impressing fingerprints on the weights
- avoid heat exchange
- avoid the change in its weight due to the presence of moisture and dust particles
- none of these
The humidity of air surrounding the balance installation should be :
- zero
- high
- it doesn't matter
- low
The temperature of the objects placed on either pans of the beam balance should be :
- different
- same
- room temperature
- the respective freezing points
The lever should be turned gently, in order to :
- ensure that the motion is smooth and quiet
- prevent the knife edges from chipping
- avoid any jerk on the balance
- none of these
The mass at the resting point gives the correct mass of the body, :
- if the resting point of a physical balance coincides with the zero resting point
- if the resting point of a physical balance coincides with a non-zero resting point
- if the resting point of a physical balance is tilted
- none of these
A balance to the true, must satisfy this condition:
- Both arms must be of equal lengths.
- Both arms must be made of same material.
- Both arms must be of same colour.
- Both pans must be of same mass.
Which type of objects should not be kept on the pan?
- Wet
- Dry
- Cold
- Hot
State whether given statement is True or False.
When a weight is hung on a spring, the spring's extension is proportional to the weight.
- True
- False
Which physical quantity is measured using Spring Balance?
- Mass
- Weight
- Density
- Volume
The final position of a pointer of a spring balance gives :
- Mass of the object
- Weight of the object
- Volume of the object
- Density of the object
State whether given statement is True or False.
Under no-load condition, the pointer of the spring balance must point at the zero mark of the scale.
- True
- False
What physical quantity is measured using Beam balance?
- Mass
- Weight
- Density
- Volume
Name the scientist who invented the spring balance?
- Robert Brown
- Robert Hooke
- Issac Newton
- Albert Einstein
In the arrangement shown, the pulleys are fixed and ideal, the strings are light, $m _{1} > m _{2}$ and $S$ is a spring balance which is itself massless. The reading of $S$ (in units of mass) is
- $m _{1} - m _{2}$
- $\dfrac {1}{2}(m _{1} + m _{2})$
- $\dfrac {m _{1}m _{2}}{m _{1} + m _{2}}$
- $\dfrac {2m _{1}m _{2}}{m _{1} + m _{2}}$
Spring balance is used for measuring :
- The force acting on an object
- The force of friction
- Magnitude of pressure
- Relative motion between objects
In spring balances, the spring is used :
- to apply forces
- to measure forces
- to absorb shocks
- to store strain energy
Spring of spring balance must be _______ in nature.
- Elastic
- Non-elastic
- Rubber
- None of these
Weight is a______
- Scalar quantity
- Vector quantity
- Both
- None
The working principle of spring balance is :
- Newton's laws of motion
- Hooke's law
- Ohm's law
- None of the above
State whether given statement is True or False.
Weight of same object differs at different distances from the equator.
- True
- False
The weight of an object :
- refers to the force with which it is attracted towards the earth
- refers to its inertia
- is the same as its mass but having different units
- none of these
The SI unit of weight is :
- Kg
- Newton
- Pounds
- Tonne
State whether given statement is True or False.
Weight remains constant at all places.
- True
- False
A spring balance has a scale reading from 0 to 50 kg. The length of the scale is 20 cm. A body suspended to the spring balance when displaced and released oscillates with a period of $0.6$ second. The mass off the body is:
- 15 kg
- 22 kg
- 50 kg
- 0.5 kg
A spring balance reads $10kg$ when a bucket of water is suspended from it. What is the reading on the spring balance when an ice cube of mass $1.5kg$ is into the bucket
- 22.5 kg
- 2.25 kg
- 1.15 kg
- 11.5 kg
A child stands on a bathroom scale while riding in an elevator. The child's weight when the elevator is not moving is 100 Ibs. What does the scale read when the elevator accelerates upward while travelling downward?
- greater than 100 Ibs
- less than 100 Ibs
- exactly 100 Ibs
- The same as it reads when accelerating downward while travelling upward, by symmetry.
A body of mass $32 ,kg$ is suspended by a spring balance from the roof of a vertically operating lift and going downward from rest. At the instants the lift has covered $20 ,m$ and $50 ,m$, the spring balance showed $30 ,kg$ and $36 ,kg$ respectively. Then the velocity of the lift is:
- decreasing at $20 \,m$ and increasing at $50 \,m$
- increasing at $20 \,m$ and decreasing at $50 \,m$
- continuously decreasing at a steady rate throughout the journey
- constantly increasing at constant rate throughout the journey.
The two arms of a balance are of unequal length. An object when placed in the left pan of the balance weighs 4kg. The same object when placed in the right pan of the balance weighs 9 kg. The actual (or) true mass of the object is
- $5.5kg$
- $6kg$
- $6.5kg$
- $7kg$
A $20 N$ metal block is suspended by a spring balance. A beaker containing some water is placed on a weighing machine which reads $40 N$. The spring balance is now lowered so that the block gets immersed in the water. The spring balance now reads $16 N$4. The reading of the weighing machine will be -
- $36 N$
- $60 N$
- $44 N$
- $56 N$
Two equal masses m and m are hung from a spring balance whose scale pans differ in vertical height by h. If $\rho$ is the mean density of earth ,then what is the error in weighing?
- $\frac { 8 } { 3 } \pi \mathrm { G\rho m h }$
- $\frac { 4 } { 3 } \pi \mathrm { G\rho m h }$
- $\frac { 5 } { 3 } \pi \mathrm { G\rho m h }$
- $\infty$
A boy whose mass is $50$ kg stands on spring balance inside a lift. The lift starts to ascend with an acceleration of $2{ m/s }^{ -2 }$. The reading of the machine or balance (g = 10${ m/s }^{ -2 }$) is
- 50 kg
- zero
- 49 kg
- 60 kg
A body of mass 2 kg is hung on a spring balance mounted vertically in a lift. If the lift descends with an acceleration equal to the acceleration due to gravity g the reading of the spring balance will be
- 4 kg
- 2 X g kg
- 2/g kg
- zero
A bird is sitting in a wire cage hanging form the spring balance. Let the reading of the spring balance be $W _1$. If the bird flies about inside the cage, the reading of the spring balance is $W _2$. Which of the following is true :-
- $W _1=W _2$
- $W _1>W _2$
- $W _1 < W _2$
- Nothing definite can be pridicted
A false balance is such that the beam remains horizontal when the pans are empty. An object weighs ${ w } _{ 1 }$ when placed in one pan and ${ w } _{ 2 }$ when placed in the other pan. Then the weight W of the object is
- $\sqrt { { w } _{ 1 }{ w } _{ 2 } } $
- $\dfrac { { w } _{ 1 }+{ w } _{ 2 } }{ 2 } $
- $\dfrac { 2 }{ \sqrt { { w } _{ 1 }^{ 2 }+{ w } _{ 2 }^{ 2 } } } $
- $\sqrt { \dfrac { { w } _{ 1 }^{ 2 }+{ w } _{ 2 }^{ 2 } }{ 2 } } $
An object hangs from a spring balance. The balance indicates $30 { N }$ in air and $20 { N }$ when the object is submerged-in.water. What does the balance indicate when the object is submerged in a liquid. with a density that is half that of water ?
- $20 N$
- $25 N$
- $30 N$
- $35 N$
A man is standing on a weighting machine with a block in his hand. The machine records $W$. When he takes the block upwards with some acceleration the machine records $W _1$. When he takes the block down with some acceleration, the machine records $W _2$. Then choose correct option
- $W _1 = W = W _2$
- $W _1 < W < W _2$
- $W _2 < W < W _1$
- $W _2 = W _1 > W$
A body is suspended on a spring balance in ship sailing along the equator with a speed $V$. If $\omega$ is the angular speed of the earth and ${W} _{0}$ is the scale reading when the ship is at rest, the scale reading when the ship is sailing will be very close to:
- ${W} _{0}$
- ${W} _{0}(1+\cfrac{2\omega V}{g})$
- ${W} _{0}(1\pm\cfrac{2\omega V}{g})$
- none of these
Find the reading of the spring balance, when the elevator is going up with an acceleration of g /10 the pulley is smooth
- 3.1 kg
- 4.4 kg
- 1.8 kg
- 6.2 kg
A person of mass 50 kg stands on a weighing scale on a lift. If the lift is descending with a downwards acceleration of $9 ms^{-2}$, what would be the reading of the weighing scale ? $(g = 10 ms^-2)$
- 5 kg
- 10 kg
- 15 kg
- 20 kg
A wooden block reads 0 kg wt on a spring balanced,when the block is immersed in water the reading of spring balance will be.
$ [p _{wood} = 0.8 gm/cm^3] $
- 8 kg wt
- 2 kg wt
- 6 kg wt
- zero
If a spring balance having frequency $f$ is taken on moon (having $ gravity = g/6$) it will have a frequency of
- $6f$
- $\dfrac{f}{3}$
- ${f}$
- $3f$
What is the net force on a bathroom scale when a 100 kg person stands on it ? $(g = 10 ms^-2)$
- 100 N
- 1000 N
- 50 N
- 0 N
The weight of a balloon is $W _1$ when empty and $W _2$ when filled with air. Both are weighed in air by the same sensitive spring balance and under identical condition. Then
- $W _1=W _2$, as the weight of air in the balloon is offset by the force of buoyancy on it
- $W _2 < W _1$, due to the force of buoyancy acting on the filled balloon
- $W _2 > W _1$ as the air inside is of a greater pressure and hence has greater density than the air outside
- $W _2=W _1+$ weight of the air inside it
Which of the following is not true of the standard weights and Measures?
- Larger weights are made of iron
- Smaller weights are made of lead
- The value is written on the top
- They are either hexagonal or circular in shape
What principle is used In a newton spring balance?
- The mass of an object depends on its density.
- The mass of an object depends an the gravity pulling
- The weight of an object is directly proportional to its mass.
- The extension of the spring is directly proportional to the force pulling it.
Which of the following principle helps in the measurement of mass of the planets?
- Einstein's theory of relativity
- Newton's Law of gravitation
- Newton's Law of cooling
- Parallax Method
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.
- More than $0.5$ kg depending on the height
- Less than $0.5$ kg but not zero
- Zero
- $0.5$ kg
We can measure weights using both spring and beam balance. But on moon, which one will give accurate measuring ?
- Beam Balance
- Spring Balance
- Both
- None
What will be the reading of spring balance if a block of mass 5kg is hung to it ?
(Take g =10 $m/s^2$)
- $35 N$
- $40 N$
- $50 N$
- $60 N$
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
- Downward with constant speed
- Downward with decreasing speed
- Downward with increasing speed
- Upward with increasing speed
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.
- ${ W } _{ 1 }$ = ${ W } _{ 2 }$
- ${ W } _{ 1 }$ < ${ W } _{ 2 }$
- ${ W } _{ 1 }$ > ${ W } _{ 2 }$
- ${ W } _{ 1 }$ $\neq $ ${ W } _{ 2 }$
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.
- Is in stationary
- Accelerate upwards
- Falls freely
- Accelerate Downwards