1. Role of gravity in satellite motion

A satellite revolving around Earth moves in a circular orbit because the gravitational force provides the required centripetal force.

For circular motion, $F_c = \frac{mv^2}{r}$

and for a satellite, $F_g = \frac{GMm}{r^2}$

Here, gravity continuously pulls the satellite toward Earth, changing only the direction of its velocity.

2. What happens if gravity suddenly becomes zero?

If the gravitational force suddenly vanishes, $F = 0$

So there is no centripetal force acting on the satellite.

By Newton’s first law, if no force acts on a body, it continues to move with the same velocity in a straight line.

3. Direction of motion at that instant

At every point in a circular orbit, the instantaneous velocity of the satellite is along the tangent to the orbit.

Therefore, when gravity disappears, the satellite will continue moving:

• in a straight line
• along the tangent to the orbit
• with the same speed/velocity magnitude it had at that instant

4. Checking options

• A: "continue to move in its orbit with same velocity" → Incorrect, because without centripetal force it cannot remain in orbit.
• B: "move tangentially to the original orbit with the same velocity" → Correct.
• C: "become stationary in its orbit" → Incorrect, no reason to stop.
• D: "move towards the earth" → Incorrect, gravity is zero, so no pull toward Earth.

5. Final answer

The satellite will move tangentially to its orbit with the same velocity.

$\boxed{\text{B}}$