Tag: introduction to gravitation

Questions Related to introduction to gravitation

$1 g$ force is the force due to gravity on a mass of 

physics universe and space heliocentric model introduction to gravitation introduction to gravity

  1. $1 kg$

  2. $0.1 kg$

  3. $0.01 kg$

  4. $0.001 kg$

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Correct Option: D
Explanation:

$1 g$ force is the force due to gravity on a mass of $1 g$ or $0.001 kg$.

A force which produces an acceleration in a body equal to acceleration due to gravity on earth, when the body has a unit mass is called

physics universe and space heliocentric model introduction to gravitation introduction to gravity

  1. Gravitational unit of force

  2. Gravity force

  3. Both

  4. None

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Correct Option: A
Explanation:

Definition of gravitational unit of force: A force which produces an acceleration in a body equal to acceleration due to gravity on earth, when the body has a unit mass is called gravitational unit of force.

Gravitational unit of force produce an acceleration in a body equal to 

physics universe and space heliocentric model introduction to gravitation introduction to gravity

  1. $g$

  2. $0$

  3. $2g$

  4. unit value

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Correct Option: A
Explanation:

Acceleration due to gravity is denoted by '$g$'.
A force which produces an acceleration in a body equal to acceleration due to gravity on earth, when the body has a unit mass is called gravitational unit of force.

State whether true or false.
The direction of the gravitational force is along the line joining the tips of the two bodies.
physics universe and space heliocentric model introduction to gravitation introduction to gravity

  1. True

  2. False

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Correct Option: B
Explanation:

The direction of gravitational force is towards the line joining the body and the centre of the earth.


Hence the given statement is $False$ and correct option is $B$ 

State whether true or false.
The universal gravitational constant is independent of the intervening medium.
physics universe and space heliocentric model introduction to gravitation introduction to gravity

  1. True

  2. False

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Correct Option: A
Explanation:

Gravity is unipolar, attractive. So when it goes through a medium, there is no polarizing effect or polarizing forces. Thus the gravitational constant is independent of the intervening medium.

If the gravitational force of earth suddenly disappears, then which of the following is correct?

physics universe and space heliocentric model introduction to gravitation introduction to gravity

  1. weight of the body is zero

  2. mass of the body is zero

  3. both mass and weight become zero

  4. neither the weight nor the mass is zero

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Correct Option: A
Explanation:

Mass = $m$

Acceleration due to gravity = $g$
Weight of a body is given by, $(W) = m\times g$
When gravitational force disappears $g$ becomes zero, but the mass remains the same.
So, $W = m\times g=m\times 0$ 
Hence, $W = 0$
Correct option will be $(A)$

The orbit of the earth is an ellipse is an and not a circle. The distance between earth sun thus varies. On January 3, earth is closet to the sun (Perihelion). Similarly, earth is said to be at Aphelion, when it is farthest from the sun on ________.

physics universe and space heliocentric model introduction to gravitation introduction to gravity

  1. March, 23

  2. July, 4

  3. December, 23

  4. April, 21

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Correct Option: B
Explanation:

Earth is about 147.1 million kilometres (91.4 million miles) from the Sun at perihelion around January 3, in contrast to about 152.1 million kilometres (94.5 million miles) at aphelion around July 4, a difference of about 5.0 million kilometres (3.1 million miles).

$1 kg wt$ is equal to

physics universe and space heliocentric model introduction to gravitation introduction to gravity

  1. $9.8 N$

  2. $980N$

  3. $98 N$

  4. none of these

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Correct Option: A
Explanation:

1kgwt is equal to 9.8N.

$1 kg wt$ is equal to

physics universe and space heliocentric model introduction to gravitation introduction to gravity

  1. $980000 dynes$

  2. $9.80 dynes$

  3. $98 dynes$

  4. none of these

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Correct Option: A
Explanation:

1kgwt = 9.8 N
1Newton = 100000 dynes
=> 1 kgwt = 980000 dynes

Two identical particles of mass m are placed at a distance r from each other. If their separation is doubled, then the effect on gravitational constant will be 

physics universe and space heliocentric model introduction to gravitation introduction to gravity

  1. Gravitational constant remains same

  2. Gravitational constant becomes quadrupled

  3. Gravitational constant becomes 1/4th the actual one

  4. Gravitational constant becomes doubled

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Correct Option: A
Explanation:

Gravitational constant does not depend on masses, distances between them

Changing the distance between the masses, decreases the force between them, so that $Fr^2$ remains the same

The correct option is (a)