Tag: universe and space

Questions Related to universe and space

In MKS, the gravitational unit of force is

  1. $kgf$

  2. $gf$

  3. $N$

  4. $dyne$


Correct Option: A
Explanation:

In MKS, the gravitational unit of force is kilogramme force (kgf).

In CGS, the gravitational unit of force is

  1. $kgf$

  2. $N$

  3. $gf$

  4. $dyne$


Correct Option: C
Explanation:

In CGS, the gravitational unit of force is gramme force ($gf$).

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

  1. $1 kg$

  2. $0.1 kg$

  3. $0.01 kg$

  4. $0.001 kg$


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

  1. Gravitational unit of force

  2. Gravity force

  3. Both

  4. None


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 

  1. $g$

  2. $0$

  3. $2g$

  4. unit value


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.
  1. True

  2. False


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.
  1. True

  2. False


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?

  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


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 ________.

  1. March, 23

  2. July, 4

  3. December, 23

  4. April, 21


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

  1. $9.8 N$

  2. $980N$

  3. $98 N$

  4. none of these


Correct Option: A
Explanation:

1kgwt is equal to 9.8N.