Tag: physics

Quizzes (598) Questions (13441)

Questions Related to physics

Multiple choice physics gravitational fields representing a gravitational field gravitational field circular motion and gravitation

A force of 10 N of gravitational force in CGS units is  represented as

  1. $10 Dynes$

  2. $10^2 Dynes$

  3. $10^5 Dynes$

  4. $10^6 Dynes$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A force of 10 N of gravittional force in CGS units is represented by 10 Dynes.

Dyne is a CGS unit of force which accelerates a mass of one gram at the rate of one centimeter per second.

Multiple choice physics gravitational fields representing a gravitational field gravitational field circular motion and gravitation

The force experienced by a unit mass at a point in the gravitational field is called its

  1. gravitational intensity

  2. electric intensity

  3. magnetic intensity

  4. gravitational constant
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The force experienced by a $unit $ mass at a point in the gravitational field $=F _g=mg=1\times g=g $ $ Newton $


We know that $g$ is called as gravitational intensity 

Hence correct answer is option $A $ 

Multiple choice physics gravitational fields representing a gravitational field gravitational field circular motion and gravitation

The ratio of SI units to CGS of the gravitational intensity is

  1. $10^3:1$

  2. infinity

  3. zero

  4. $10^2:1$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Gravitational intensity is nothing but the acceleration due to gravity(g)

SI unit of g is $m/s^2=100cm/s^2$
But CGS unit of g is $cm/s^2$ 
So SI unit:CGS unit $=100:1$ 

Hence correct answer is option $D $ 

Multiple choice physics gravitational fields representing a gravitational field gravitational field circular motion and gravitation

Which of the following represents the unit for gravitational intensity?

  1. N

  2. $kgm^{-2}$

  3. $Nkg^{-1}$

  4. $ms^{-3}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Gravitational intensity is nothing but the acceleration due to gravity $=g=F _g/m$


Now we know that the SI unit of $F _g$ is $Newton(N) $ and that of $m$ is $kg$
So SI unit of $g=N/kg=Nkg^{-1}$ or $m/s^2$ 

Hence correct answer is option $C $ 

Multiple choice physics gravitational fields representing a gravitational field gravitational field circular motion and gravitation

The speed at which the gravitational field propagates is

  1. Equal to the speed of light in vacuum

  2. Less than the speed of light in vacuum

  3. More than the speed of light in vacuum

  4. Either less or more than the speed of light in

    vacuum
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The speed of gravitational waves in the general theory of relativity is equal to the speed of light in vacuum.

Multiple choice physics gravitational fields representing a gravitational field gravitational field circular motion and gravitation

The unit of (V) Gravitational Potential is

  1. $\dfrac{\text{Joule}}{kg}$

  2. $\text{Joule}$

  3. $\dfrac{\text{Joule}}{s}$

  4. $\dfrac{kg}{\text{Joule}}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Gravitational potential is defined as the Gravitational energy per unit mass of the object on the planet. Unit of energy is always joule in SI units. Hence that of potential will be Joule/kg.

Multiple choice physics gravitational fields representing a gravitational field gravitational field circular motion and gravitation

Value of gravitational constant, $'G'$ is

  1. $6.674 08 \times 10^{-11} m^3 kg^{-1} s^{-2}$

  2. $4.674 08 \times 10^{-11} m^3 kg^{-1} s^{-2}$

  3. $6.674 08 \times 10^{11} m^3 kg^{-1} s^{-2}$

  4. $6.674 08 \times 10^{-11} m^3 kg^{-2} s^{2}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The value of G in SI units is $6.67408\times {10^{-11}}$

And the unit is $ Newton.metre^2/kg^2 $
Newton is $kg.m.s^{-2} $
Hence it becomes $ m^3.kg^{-1}.s^{-2} $

Multiple choice physics gravitational fields representing a gravitational field gravitational field circular motion and gravitation

Gravitational field is 

  1. directly proportional to square of the distance between two masses.

  2. inversely proportional to square of the distance between two masses.

  3. directly proportional to the distance between two masses.

  4. inversely proportional to the distance between two masses.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The gravitational field is the region in which the gravitational force can be experienced or its presence can be felt. The intensity of gravitational field is the force acting on a unit mass of a body. 

Gravitational force is given by $Force = \dfrac{GMm} {R^2}$, 
where $G$ is gravitational constant, $M$ is the mass of the body which is creating the gravitational force, $m$ is the mass of the body which is undergoing gravitational force and $R$ is the distance between them. You can see that this force is inversely proportional to the square of the distance between the two masses. Gravitational field is given by gravitational force / mass of the 2nd body i.e. $m$. 
$Field = \dfrac{GM}{R^2}$. Hence it is inversely proportional to square of the distance between two masses.