Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics forces - vectors and moments the turning of couple couple rotational motion of a rigid body and moment of inertia turning effect of force

State whether true or false.
A couple can never be replaced by a single force.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A couple is defined as a pair of two equal and opposite parallel forces acting along two different lines. A couple can produce roatation in the body but not the translational motion. A single force can produce translation motion in the body. Thus the given statement is true that a couple can never be replaced by a single force.

Multiple choice physics forces - vectors and moments the turning of couple couple rotational motion of a rigid body and moment of inertia turning effect of force

State whether true or false.
Only a couple can produce pure rotation in a body.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A couple is defined as a pair of two equal and opposite parallel forces acting along two different lines. Since net force acting on the body is zero, so the body is in translatory equilibrium. A couple produces torque which rotates the body. Thus the given statement is true that only a couple can produce pure rotation in a body.

Multiple choice physics forces - vectors and moments the turning of couple couple rotational motion of a rigid body and moment of inertia turning effect of force

While opening a tap with two fingers, the forces applied by the fingers are:

  1. equal in magnitude

  2. parallel to each other

  3. opposite in direction

  4. all the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

A couple has to be applied to the tap in order to open it. A couple is the combination of two equal and opposite parallel forces acting at different axes. Thus option D is correct.

Multiple choice physics forces - vectors and moments the turning of couple couple rotational motion of a rigid body and moment of inertia turning effect of force

$ML^2T^{-2}$ is the dimensional formula for

  1. moment of inertia

  2. pressure

  3. elasticity

  4. couple acting on a body
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

$\left[ MOI \right] =\left[ M{ R }^{ 2 } \right] =\left[ { M }^{ 1 }{ L }^{ 2 }{ T }^{ 0 } \right] \ \left[ Pressure \right] =\left[ N/{ M }^{ 2 } \right] =\left[ { M }^{ 1 }{ L }^{ -1 }{ T }^{ -2 } \right] \ \left[ Couple \right] =\left[ N.{ M } \right] =\left[ { M }^{ 1 }{ L }^{ 2 }{ T }^{ -2 } \right] $

Multiple choice physics forces - vectors and moments the turning of couple couple rotational motion of a rigid body and moment of inertia turning effect of force

An automobile engine develops $100$ $kW$ when rotating at a speed of $1800\ rev/min$. The torque it delivers is

  1. $3.33\ N-m$

  2. $200\ N-m$

  3. $530.5\ N-m$

  4. $2487\ N-m$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$Power\quad P=100kW\quad =100000W\ w=1800\times \cfrac { 2\pi  }{ 60 } \quad rad/s\ \quad =60\pi \quad rad/s\ P=torque\times w\ torque=530.5\quad Nm$

Multiple choice physics measurements and uncertainties graphs of the form y=ax^2+bx+c some more types of functions functions and their graphs

 Years Production of Car P  Production of Car Q Production of Car R 
2001  76  59  28
2002  82  62  36
2003  65  47 42 
2004  70  54  31
2005  85  57  49
2006  80  68  38

Direction (1-2) : Study the following table which shows the production of three different types of cars over the years.
The difference between the total production of three cars in the year $2004$ and $2006$ is _____.

  1. $11$

  2. $43$

  3. $31$

  4. $28$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Total production of cars In year $2004$
$= 70 + 54 + 31 = 155$
Total production of cars in year $2006$
$= 80 + 68 + 38 = 186$
Hence, difference between the total production of three cars in the year $2004$ and $2006$
$= 186- 155 = 31$

Multiple choice physics measurements and uncertainties graphs of the form y=ax^2+bx+c some more types of functions functions and their graphs

 Years Production of Car P  Production of Car Q Production of Car R 
2001  76  59  28
2002  82  62  36
2003  65  47 42 
2004  70  54  31
2005  85  57  49
2006  80  68  38

Direction (1-2) : Study the following table which shows the production of three different types of cars over the years.
The average production of which of the following types of cars was maximum?

  1. $Q$

  2. $P$

  3. $R$

  4. All are equal
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Average production of Car $P$
$=$ $\dfrac {\text{Sum of production of Car P in each year}}{\text{Total number of years}}$
$=$ $\dfrac {76 + 82 + 65 + 70 + 85 + 80}{6}$ $=$ $\dfrac {458}{6}$ $= 76.33$
Average production of Car $Q$
$=$ $\dfrac {59 + 62 + 47 + 54 + 57 + 68}{6}$ $=$ $\dfrac {347}{6}$ $= 57.83$
Average production of Car $R$
$=$ $\dfrac {28 + 36 + 42 + 31 + 49 + 38}{6}$ $=$ $\dfrac {224}{6}$ $= 37.33$
Clearly, average production of Car $P$ is greater than Car $Q$ and Car $R$.
Hence, the average production of Car $P$ is maximum.

Multiple choice physics space missions launching of an artificial satellites around the earth launching of satellite india’s space programmes

ENERGY OF AN ORBITING SATELLITE
In motion of an object under the gravitational influence of another object. Which of the following quantities is not conserved?

  1. Angular momentum

  2. mass of an object

  3. Total mechanical energy

  4. Linear momentum
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

While considering the motion of an object under the gravitational influence of another object, angular momentum and total mechanical energy are conserved.Linear momentum is not conserved

Multiple choice physics space missions launching of an artificial satellites around the earth launching of satellite india’s space programmes

The minimum distance of a satellite from the centre of the earth is 3R, where R is the radius of 2GM What is the earth. The mass of earth is M. The maximum speed of the satellite is $\sqrt { \frac { 2 G M } { 3 R } }$ radius of curvature at the point of minimum distance?

  1. 6 R

  2. 4 R

  3. 3 R

  4. $\frac { 9 R } { 2 }$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$\begin{array}{l} F=\dfrac { { G\left( M \right) m } }{ { { { \left( { 3R } \right)  }^{ 2 } } } }  \ \Rightarrow a=\dfrac { { GM } }{ { 9{ R^{ 2 } } } }  \ \therefore \dfrac { { { V^{ 2 } } } }{ { R' } } =a \ \Rightarrow \dfrac { { 2GM } }{ { 3R.R' } } =\dfrac { { GM } }{ { 9{ R^{ 2 } } } }  \ \Rightarrow R'=6R \ Hence, \ option\, \, A\, \, is\, \, correct\, \, answer. \end{array}$