| 1 |
Drag force increases if speed of the object moving through the fluid: |
Increases
Decreases
Remains constant
None of these
|
| 2 |
Fog droplets are suspended in air when their weight is balanced by: |
Force of gravity
Upward trust due to air
Surface tension
None of these
|
| 3 |
At high speed, fluid friction _____ and fuel consumption ___,: |
Increases, decreases
Increases, increases
Decreases, increases
None of these
|
| 4 |
Two copper balls of 1 cm and 2 cm in diameter are simultaneously dropped in the same viscous medium. The terminal velocity of bigger ball is: |
Not affected due to its size
Twice that of small size ball
Four times that of small size ball
1/4th of that of small size ball
|
| 5 |
When the droplet moves with terminal velocity in a fluid, the net force acting on the droplet is: |
F<sub>D</sub>-mg
Zero
mg-F<sub>D</sub>
None of these
|
| 6 |
The _____ viscous the medium is _____, is the value of terminal velocity of the droplet: |
More, lesser
Lesser, more
Both A and B
Lesser, lesser
|
| 7 |
Terminal velocity is the maximum velocity attained by a spherical droplet when the drag force______the weight of droplet: |
Is smaller than
Is greater than
Becomes equal to
None of these
|
| 8 |
A massive object falls through a fluid: |
Faster
Slower
Slowest
None
|
| 9 |
High speed meteors rushing through air reduces to ashes because of: |
Force of gravity
High resistance of air
Drag force
None of these
|
| 10 |
Stock's law holds for: |
Motion through free space
Motion through viscous medium
Bodies of all shapes
None of these
|
| 11 |
Viscosity of water is ______ that of air but ___ that of plasma. |
More, more
Less, more
Less, less
More, less
|
| 12 |
Fluid friction is _____ the friction between two solid surfaces: |
Greater than
Smaller than
Equal to
None of these
|
| 13 |
Density of fluid is defined as: |
Its volume to mass ratio
Product of volume and mass
Its mass of volume ratio
None of these
|
| 14 |
Unit of viscosity is: |
Kg m<sup>-1</sup>sec<sup>-1</sup>
N s m<sup>-2</sup>
J s m<sup>-3</sup>
All of these
|
| 15 |
Glycerin has viscosity _____ the viscosity of water: |
More than
Equal to
Less than
None of these
|
| 16 |
A body is moving through a viscous medium eventually comes to rest because of: |
Force of gravity
Force of friction
Its weight
Both A and C
|
| 17 |
N s m-2is unit of: |
Drag force
Pressure
Surface tension
Coefficient of viscosity
|
| 18 |
Machine parts are jammed due to: |
Increasing in viscosity of lubricant
Decreasing in viscosity of lubricant
Decreasing in surface tension of lubricant
None of these
|
| 19 |
The body passing a viscous medium affected by: |
One force only
Two forces only
Four forces
None of these
|
| 20 |
The resistance offered by a fluid to a solid moving inside it is called: |
Drag force
Surface force
Viscosity
None of these
|
| 21 |
The property of fluids due to which they resist their own flow is called: |
Drag force
Surface tension
Viscosity
None of these
|
| 22 |
In case of planets, the necessary acceleration is provided by: |
Gravitational force
Coulomb force
Frictional force
None of these
|
| 23 |
A body can have constant velocity when it follows: |
A circular path
A rectilinear path
Trajectory of a projectile
None of these
|
| 24 |
The instantaneous acceleration of a body moving with constant speed in a circle: |
Remains constant
Is called centripetal acceleration
Tangential acceleration
None of these
|
| 25 |
When a body moves with a constant speed in a circle: |
No work is done on it
No acceleration is produced in the body
Velocity remains constant
None of these
|
| 26 |
When an object moves with a uniform angular velocity, then its instantaneous angular velocity is equal to: |
Zero
Its average velocity
Its angular displacement
None of these
|
| 27 |
The angular speed of a particle moving along a circular path is 5 Pie rad sec-1, Its period of motion is: |
2.5 sec
0.06 sec
15.7 sec
0.4 sec
|
| 28 |
Angular velocity is a: |
Scalar quantity
Vector quantity
Complex quantity
None of these
|
| 29 |
Circular motion is an example of motion in: |
One dimension
Two dimensions
Three dimensions
None of these
|
| 30 |
The useful unit of the angular displacement in SI unit is: |
Degree
Revolution
Radian
Metre
|