Uniform Circular Motion - Free MCQ Practice Test with solutions, NEET Physics

CONCEPT:

• Uniform motion is the type of motion where a moving object traces equal distances in equal intervals of time.
  • Since the distance and time intervals are the same, speed is constant in uniform motion.
• Uniform circular motion is where a moving object traces a circular path with constant speed.
  • A circle is assumed to be a polygon with infinitely many sides such that each side approximates to a point.
  • So, if the object moving on a circular path undergoes a change in direction at every point.
  • Since direction changes and speed remains constant, velocity is varying.

EXPLANATION:

• Velocity is changing in a uniform circular motion as the direction of the object keeps changing at every point.
• Acceleration is the rate of change of velocity. Since velocity keeps changing at every instant, acceleration also changes.

Therefore, both acceleration and velocity changes in a uniform circular motion.

When an object moves along a circular path, it is called circular motion. During such a motion, the direction of motion at any point is given by the tangent at that point which changes continuously.

• Velocity is transverse (t): This is because the velocity is always tangent to the circle.
• Acceleration has both radial and transverse components: The acceleration has a radial component (directed along the radius, responsible for maintaining circular motion) and a transverse component (directed tangentially, responsible for changes in speed).

Therefore, the correct multiple answers are:

2. Uniform, constant
3. Non-uniform, varying

• Non-uniform, constant – This is incorrect. If the motion is non-uniform, the speed cannot be constant.

• Uniform, constant – This is correct. In uniform circular motion, the speed is constant.

• Non-uniform, varying – This is correct. In non-uniform circular motion, the speed varies.

• Uniform, varying – This is incorrect. If the motion is uniform, the speed must remain constant, so it cannot be varying.

An accelerating body is an object that is changing its velocity. And since velocity is a vector that has both magnitude and direction, a change in either the magnitude or the direction constitutes a change in the velocity.
Hence a uniform circular motion is a accelerated motion because direction of motion keeps on changing

To describe the motion of a particle along a circle with a uniform speed. We need two variable, either x and y, or r and θ. Therefore, the motion of the particle is two-dimensional.

An object moving in uniform circular motion is moving in a circle with a uniform or constant speed. The velocity vector is constant in magnitude but changing in direction.
Hence, the motion of a racing car on a circular track changes it speed, that is, it increases or decreases speed during the drive not a case of uniform circular motion.