1489 + Mcqs in Science Page 15 McqOptions

701.	A mechanical system produces heat energy because of
A.	Radiation
B.	Convection
C.	Lubrication
D.	Friction
Answer» E.

Discussion

702.	Jackson is rearranging his study. He decides to move the file cabinet to the comer of the room. He starts pushing the file cabinet over the floor. Which force is acting between the floor and the file cabinet?
A.	Tension
B.	Frictional
C.	Compressive
D.	Gravitational
Answer» C. Compressive

Discussion

703.	A magnet can pull an iron nail toward itself. The maximum distance from which the magnet (shown in the given figure) can pull the nail is labelled as d.On which surface will this distance d be relatively large?
A.	Cemented surface
B.	Carpeted surface
C.	Sandy surface
D.	Oily surface
Answer» E.

Discussion

704.	On which of the following types of roads will a sledge travel the farthest?
A.	Dry road
B.	Icy road
C.	Carpeted road
D.	Cemented road
Answer» C. Carpeted road

Discussion

705.	Ted learns about force of friction and tries out different ways of reducing as well as increasing the friction on the surface of his driveway. In order to reduce the friction on the surface of the drive way, Ted should
A.	Cover it with small pebbles
B.	Cover it with sand
C.	Spread grit on it
D.	Pour oil on it
Answer» E.

Discussion

706.	Olivia pushes a toy car on a rough surface. The toy car travels 4 m before stopping. The distance travelled by the toy car can be increased by
A.	Loading the toy car with a stone
B.	Removing the wheels of the toy car
C.	Pushing the toy car with less force
D.	Pushing the toy car on a smooth surface
Answer» E.

Discussion

707.	John pushes a table with wheels under it. At the same time, Abraham pushes a table without any wheels under it. Both the .tables weigh the same. The two tables move at the same speed, but John applies lesser force than Abraham.Which force is reduced by the wheels under John's table?
A.	Magnetic
B.	Frictional
C.	Electrostatic
D.	Gravitational
Answer» C. Electrostatic

Discussion

708.	Two boxes, having the same weight, are kept between two vertical walls. Calvin lifts one of the boxes (against the pull of gravitational force) with the help of a rope. Before lifting the second box, he lubricates the vertical walls with oil. As a result, he has to apply less force to lift the second box. Which force is reduced as a result of the lubrication of the walls?
A.	Gravitational
B.	Compressive
C.	Frictional
D.	Magnetic
Answer» D. Magnetic

Discussion

709.	Tony is playing carom along with his friends. After completing 2 games, some talcum powder is rubbed on to the board. Talcum powder is used on the board to
A.	Reduce its friction
B.	Decrease its mass
C.	Improve its fragrance
D.	Improve its conductivity
Answer» B. Decrease its mass

Discussion

710.	A body of mass 25 kg, is placed on a horizontal surface whose coefficient of friction 0.25. Find the frictional force action on it. Take (\[g=10m{{s}^{-2}}\])
A.	150 N
B.	175 N
C.	62.5 N
D.	53.3 N
Answer» D. 53.3 N

Discussion

711.	There are three types of friction, namely sliding, static, and rolling. They are respectively denoted as \[{{f}_{sl}},{{f}_{st,}}\] and \[{{f}_{roll}}\]. On a given surface, the given frictional forces are related as
A.	\[{{f}_{sl}}>{{f}_{st}}>{{f}_{roll}}\]
B.	\[{{f}_{st}}>{{f}_{sl}}>{{f}_{roll}}\]
C.	\[{{f}_{st}}>{{f}_{roll}}>{{f}_{sl}}\]
D.	\[{{f}_{sl}}>{{f}_{roll}}>{{f}_{st}}\]
Answer» C. \[{{f}_{st}}>{{f}_{roll}}>{{f}_{sl}}\]

Discussion

712.	If the force of friction were not to exist, then it would be almost impossible to both
A.	Speak and listen
B.	Write and walk
C.	Speak and walk
D.	Write and listen
Answer» C. Speak and walk

Discussion

713.	Joe slides a plank of wood over the floor. As the wood plank slides over the floor, its speed can be increased the most if
A.	The floor is lubricated
B.	It is coated with oil
C.	Balls are placed under it
D.	It is smoothed with sand paper
Answer» D. It is smoothed with sand paper

Discussion

714.	In order to reduce the friction of a wheel-axle, a bicycle uses
A.	gears
B.	brakes
C.	pedals
D.	ball bearings
Answer» E.

Discussion

715.	Ted learns about force of friction. He tries out different ways of reducing as well as increasing the friction on the surface of his driveway. In order to increase the friction on the surface of the driveway, Ted should
A.	Cover it with small pebbles
B.	Cover it with wax
C.	Pour water on it
D.	Pour oil on it
Answer» B. Cover it with wax

Discussion

716.	Vishnu and Mahesh are pushing a heavy box placed on a floor, as shown in the given figure. The arrow over the box shows the direction of motion of the box. Vishnu is applying a force of magnitude \[{{F}_{v}}\] and Mahesh is applying a force of magnitude \[{{F}_{m}}\]. Which of the following pairs of forces have the same direction?
A.	\[{{F}_{v}}\]and frictional force
B.	\[{{F}_{m}}\]and frictional force
C.	\[{{F}_{v}}\]and gravitational force
D.	\[{{F}_{m}}\] and gravitational force
Answer» C. \[{{F}_{v}}\]and gravitational force

Discussion

717.	Four similar boxes are labelled I, II, III, and IV. The masses of I and III are equal and the masses of II and IV are equal. The mass of box I is smaller than that of box II. Boxes I and II are placed in a grass field and boxes III and IV are placed on a marble floor. Which box requires the maximum force to be moved?
A.	I
B.	II
C.	III
D.	IV
Answer» C. III

Discussion

718.	A formula one car is shown in the given figure. Formula one (F1) is one of the most famous and fastest racing events of the world. In this sport, cars can acquire speeds as high as 320 km/hr. One of the reasons of the high speeds is the design of the F1 cars. The shape of the car helps in
A.	Reducing the air drags
B.	Reducing the car weight
C.	Increasing the car efficiency
D.	Increasing the consumption fuel
Answer» B. Reducing the car weight

Discussion

719.	In order to move a stationary object, an interlocking between the two surfaces must be overcome. The minimum force required to overcome this interlocking is known as
A.	Static friction
B.	Rolling friction
C.	Sliding friction
D.	Kinetic friction
Answer» B. Rolling friction

Discussion

720.	Four cubical boxes, made up of the same material, are placed on the ground and are pushed with a constant force, \[{{d}_{1}},{{d}_{2}},{{d}_{3}}\], and \[{{d}_{4}}\] are the distances travelled by the boxes. They are related as \[{{d}_{3}}>{{d}_{2}}>{{d}_{4}}>{{d}_{1}}\]. The sides \[{{a}_{1}},{{a}_{2}},{{a}_{3}},\] and \[{{a}_{4}}\] of the respective boxes are related as
A.	\[{{a}_{1}}>{{a}_{2}}>{{a}_{3}}>{{a}_{4}}\]
B.	\[{{a}_{1}}>{{a}_{4}}>{{a}_{2}}>{{a}_{3}}\]
C.	\[{{a}_{3}}>{{a}_{2}}>{{a}_{4}}>{{a}_{1}}\]
D.	\[{{a}_{4}}>{{a}_{3}}>{{a}_{2}}>{{a}_{1}}\]
Answer» C. \[{{a}_{3}}>{{a}_{2}}>{{a}_{4}}>{{a}_{1}}\]

Discussion

721.	Friction arises due to _______ in the surfaces of objects.
A.	Softness
B.	Irregularities
C.	Atmospheric pressure
D.	Magnetism
E.	None of these
Answer» C. Atmospheric pressure

Discussion

722.	The force which always opposes the motion of an object is:
A.	Gravitational force
B.	Frictional force
C.	Magnetic force
D.	Muscular force
E.	None of these
Answer» C. Magnetic force

Discussion

723.	_____ is involved in filling up the liquid into the syringe.
A.	Atmospheric pressure
B.	Magnetic pressure
C.	Frictional force
D.	Electrostatic force
E.	None of these
Answer» B. Magnetic pressure

Discussion

724.	When would depression in the ground be the most:
A.	When a man stands on the ground
B.	When a lies upside down on the ground.
C.	When a tree falls on the ground.
D.	All the above
E.	None of these
Answer» B. When a lies upside down on the ground.

Discussion

725.	Unit of measuring loudness is:
A.	Hertz
B.	Metre/Second
C.	Metre
D.	Decibel
E.	None of these
Answer» E. None of these

Discussion

726.	Which one of the following statements is correct? (i) Loudness of sound is directly proportional to the square of amplitude vibrations. (ii) Sound can travel through vacuum. (iii) Speed of sound is maximum in solids. (iv) The outer part of ear is called ear canal.
A.	(i) and (ii)
B.	(ii) and (iii)
C.	(i) and (iii)
D.	(i) and (iv)
E.	None of these
Answer» D. (i) and (iv)

Discussion

727.	If we strike a wooden table with a steel spoon lightly we hear a feeble sound but if we hit the wooden table hard with steel spoon, a loud sound is heard because:
A.	Amplitude of vibration is high in case of loud sound.
B.	Amplitude of vibration is low in case of feeble sound.
C.	Both [a] and [b]
D.	Either [a] or [b]
E.	None of these
Answer» C. Both [a] and [b]

Discussion

728.	Frequency of vibration is directly proportional to___ of sound.
A.	Amplitude
B.	Loudness
C.	Pitch
D.	Time period
E.	None of these
Answer» D. Time period

Discussion

729.	If the amplitude of a vibration is doubled then the loudness of the sounds will become:
A.	Half
B.	One-fourth
C.	Doubled
D.	Four times
E.	None of these
Answer» E. None of these

Discussion

730.	S.I. unit of pressure is?
A.	Newton
B.	Pascal
C.	Metre
D.	Newton
E.	None of these
Answer» F.

Discussion

731.	Friction can be reduced by:
A.	Polishing the surface.
B.	Greasing the surfaces.
C.	Using wheels.
D.	All the above
E.	None of these
Answer» E. None of these

Discussion

732.	While playing tugs of war we often feel that the rope is slipping through our hands. We rub soil on our hands to:
A.	Decrease friction
B.	Increase friction
C.	Increase pressure
D.	To increase area of contact
E.	None of these
Answer» C. Increase pressure

Discussion

733.	As we go up in the atmosphere from the surface of earth, the atmosphere pressure decreases due to decrease in ______ of air above us.
A.	Length
B.	Weight
C.	Colour
D.	Mixture
E.	None of these
Answer» C. Colour

Discussion

734.	100 Pascal is equal to:
A.	\[100\text{ }Newton\]
B.	\[1000\,N/{{m}^{2}}\]
C.	\[100\,\,N/{{m}^{2}}\]
D.	\[10,000\,\,N/{{m}^{2}}\]
E.	None of these
Answer» D. \[10,000\,\,N/{{m}^{2}}\]

Discussion

735.	A list of mediums is given below: (i) Wood (ii) Water (iii) Air (iv) Vacuum In which of these mediums can sound travel?
A.	(i) and (ii) only
B.	(i), (ii) and (iii) only
C.	(iii) and (iv) only
D.	(ii), (iii) and (iv) only
E.	None of these
Answer» C. (iii) and (iv) only

Discussion

736.	The maximum friction will be observed between two objects when:
A.	One object which just tends to move over the surface of the other object.
B.	One object moves slowly over the surface of another object.
C.	One object rolls over the surface of another object.
D.	All the above
E.	None of these
Answer» B. One object moves slowly over the surface of another object.

Discussion

737.	If the same force is applied on a toy car, on which of the following. It will move with maximum speed?
A.	Wooden surface
B.	Uneven surface
C.	Polished marble surface
D.	Brick wall
E.	None of these
Answer» D. Brick wall

Discussion

738.	Which one of the following forces can be applied only when the body is in contact with the object?
A.	Frictional force
B.	Muscular force
C.	Gravitational force
D.	Both [a] and [b]
E.	None of these
Answer» B. Muscular force

Discussion

739.	A boy is pushing a table from left to right. The force of friction will act on the table:
A.	From left to right
B.	Vertically downwards
C.	Vertically upwards
D.	From right to left
E.	None of these
Answer» E. None of these

Discussion

740.	Which of the following produces sound in Dholak?
A.	Stretched strings
B.	Air column
C.	Stretched membrane
D.	Keys
E.	None of these
Answer» D. Keys

Discussion

741.	___ shaped objects will face minimum resistance while moving in under:
A.	Rectangular
B.	Square
C.	Oblongata
D.	Streamlined
E.	None of these
Answer» E. None of these

Discussion

742.	A force is applied on an object which is in rest. If frictional force is equal to applied force then the body:
A.	Will move in forward direction.
B.	Will move in backward direction.
C.	Will remain in rest.
D.	Will move in upward direction.
E.	None of these
Answer» D. Will move in upward direction.

Discussion

743.	School bags have wide straps so as to: (i) Increase the pressure on the shoulder. (ii) Decrease the pressure on the shoulder. (iii) Make the bag's weight fall over a small area of the shoulder. (iv) Make the bag's weight fall over a large area of the shoulder.
A.	(ii) and (iii)
B.	(i) and (iii)
C.	(i) and (ii)
D.	(ii) and (iv)
E.	None of these
Answer» E. None of these

Discussion

744.	When the force applied in the directions of motion of the object, its spa
A.	Decreases
B.	Increases
C.	Either increases or decreases
D.	All the above
E.	None of these
Answer» C. Either increases or decreases

Discussion

745.	In which of the following more frictional force will be observed?
A.	A man walking on a glass.
B.	A man walking on ice.
C.	A man walking on a concrete road.
D.	All the above
E.	None of these
Answer» C. A man walking on a concrete road.

Discussion

746.	Atmospheric pressure _______ with increasing height.
A.	Increases
B.	Decreases
C.	Remains same
D.	Expands
E.	None of these
Answer» C. Remains same

Discussion

747.	We can conclude that force can change the shape of an object by which of the following examples?
A.	Breaking of glass on hammering.
B.	Squeezing of a toothpaste tube.
C.	Stretching of a spring on applying force.
D.	All the above
E.	None of these
Answer» E. None of these

Discussion

748.	Force X and Y are applied on an object in opposite directions. If the magnitude of force Y is more than the X, then the net force acting on the object .
A.	X - Y is in the direction of Y.
B.	Y - X is in the direction of Y.
C.	X - Y is in the direction of X.
D.	Y - X is in the direction of X.
E.	None of these
Answer» E. None of these

Discussion

749.	How does the pressure exerted by a liquid change?
A.	Increases with depth
B.	Decreases with depth
C.	Remains constant
D.	First increases and then decreases
Answer» B. Decreases with depth

Discussion

750.	What causes the atmospheric pressure?
A.	The sky above our head
B.	The air surrounding the earth
C.	The gravitational force of the sun and other planets
D.	The mass of the earth
Answer» C. The gravitational force of the sun and other planets

Discussion

Explore topic-wise MCQs in 8th Class.

A mechanical system produces heat energy because of

Jackson is rearranging his study. He decides to move the file cabinet to the comer of the room. He starts pushing the file cabinet over the floor. Which force is acting between the floor and the file cabinet?

A magnet can pull an iron nail toward itself. The maximum distance from which the magnet (shown in the given figure) can pull the nail is labelled as d.On which surface will this distance d be relatively large?

On which of the following types of roads will a sledge travel the farthest?

Ted learns about force of friction and tries out different ways of reducing as well as increasing the friction on the surface of his driveway. In order to reduce the friction on the surface of the drive way, Ted should

Olivia pushes a toy car on a rough surface. The toy car travels 4 m before stopping. The distance travelled by the toy car can be increased by

John pushes a table with wheels under it. At the same time, Abraham pushes a table without any wheels under it. Both the .tables weigh the same. The two tables move at the same speed, but John applies lesser force than Abraham.Which force is reduced by the wheels under John's table?

Tony is playing carom along with his friends. After completing 2 games, some talcum powder is rubbed on to the board. Talcum powder is used on the board to

A body of mass 25 kg, is placed on a horizontal surface whose coefficient of friction 0.25. Find the frictional force action on it. Take (\[g=10m{{s}^{-2}}\])

There are three types of friction, namely sliding, static, and rolling. They are respectively denoted as \[{{f}_{sl}},{{f}_{st,}}\] and \[{{f}_{roll}}\]. On a given surface, the given frictional forces are related as

If the force of friction were not to exist, then it would be almost impossible to both

Joe slides a plank of wood over the floor. As the wood plank slides over the floor, its speed can be increased the most if

In order to reduce the friction of a wheel-axle, a bicycle uses

Ted learns about force of friction. He tries out different ways of reducing as well as increasing the friction on the surface of his driveway. In order to increase the friction on the surface of the driveway, Ted should

A formula one car is shown in the given figure. Formula one (F1) is one of the most famous and fastest racing events of the world. In this sport, cars can acquire speeds as high as 320 km/hr. One of the reasons of the high speeds is the design of the F1 cars. The shape of the car helps in

In order to move a stationary object, an interlocking between the two surfaces must be overcome. The minimum force required to overcome this interlocking is known as

Friction arises due to _______ in the surfaces of objects.

The force which always opposes the motion of an object is:

_____ is involved in filling up the liquid into the syringe.

When would depression in the ground be the most:

Unit of measuring loudness is:

Which one of the following statements is correct? (i) Loudness of sound is directly proportional to the square of amplitude vibrations. (ii) Sound can travel through vacuum. (iii) Speed of sound is maximum in solids. (iv) The outer part of ear is called ear canal.

If we strike a wooden table with a steel spoon lightly we hear a feeble sound but if we hit the wooden table hard with steel spoon, a loud sound is heard because:

Frequency of vibration is directly proportional to___ of sound.

If the amplitude of a vibration is doubled then the loudness of the sounds will become:

S.I. unit of pressure is?

Friction can be reduced by:

While playing tugs of war we often feel that the rope is slipping through our hands. We rub soil on our hands to:

As we go up in the atmosphere from the surface of earth, the atmosphere pressure decreases due to decrease in ______ of air above us.

100 Pascal is equal to:

A list of mediums is given below: (i) Wood (ii) Water (iii) Air (iv) Vacuum In which of these mediums can sound travel?

The maximum friction will be observed between two objects when:

If the same force is applied on a toy car, on which of the following. It will move with maximum speed?

Which one of the following forces can be applied only when the body is in contact with the object?

A boy is pushing a table from left to right. The force of friction will act on the table:

Which of the following produces sound in Dholak?

___ shaped objects will face minimum resistance while moving in under:

A force is applied on an object which is in rest. If frictional force is equal to applied force then the body:

School bags have wide straps so as to: (i) Increase the pressure on the shoulder. (ii) Decrease the pressure on the shoulder. (iii) Make the bag's weight fall over a small area of the shoulder. (iv) Make the bag's weight fall over a large area of the shoulder.

When the force applied in the directions of motion of the object, its spa

In which of the following more frictional force will be observed?

Atmospheric pressure _______ with increasing height.

We can conclude that force can change the shape of an object by which of the following examples?

Force X and Y are applied on an object in opposite directions. If the magnitude of force Y is more than the X, then the net force acting on the object .

How does the pressure exerted by a liquid change?

What causes the atmospheric pressure?