Test: Motion and Measurement of Distances - Class 6 MCQ

When a bullet is fired from a gun, it moves in a straight line along a particular direction. This type of motion, where the object moves along a straight path, is called rectilinear motion. The bullet moves along this path until it is acted upon by forces like gravity and air resistance. Thus, the correct answer is rectilinear motion.

The other options do not describe the motion of a bullet:

Option A: Non-periodic motion refers to motion that does not repeat in a regular pattern, which is not the case for a bullet's motion.

Option C: Random motion refers to unpredictable and erratic motion, which is not applicable here.

Option D: Circulatory motion refers to circular motion, which is not the case for a bullet's straight path.

To find the least count of a scale that is divided into equal divisions, we can follow these steps:

1. Understand the Total Length and Divisions: We know that 1 cm on the scale is divided into 20 equal divisions.
2. Convert the Total Length to Millimeters: Since 1 cm is equal to 10 mm, we can express the total length in millimeters:
   1 cm = 10 mm
3. Calculate the Value of Each Division: To find the value of one division, we divide the total length (in mm) by the number of divisions:
   Value of each division = 10 mm/20 = 0.5 mm
4. Determine the Least Count: The least count of the scale is the value of one division, which we have calculated to be 0.5 mm.

The least count of the given scale is 0.5 mm.

A hectare is a unit of area commonly used in measuring land. It is equivalent to 10,000 square meters or 2.471 acres. It is often used in agriculture, forestry, and real estate to measure large areas of land.

The other options are incorrect:

Option A: Volume refers to the amount of space an object occupies and is measured in cubic units like cubic meters.

Option B: Length refers to the measurement of distance, which is measured in units like meters or kilometers.

Option D: Mass refers to the quantity of matter in an object, measured in units like kilograms or grams.

If we observe the motion of the bob in the above figure, we see it moves to and fro about a point ‘O’. This type of motion is known as oscillatory motion. Also the motion of simple pendulum is a periodic motion as it takes equal time to complete one oscillation.
The other options are incorrect:

Option B: Rotatory motion involves objects moving in a circular path, such as a wheel spinning.

Option C: Curvilinear motion refers to motion along a curved path, but the pendulum swings along an arc, not in a general curved path.

Option D: Rectilinear motion is straight-line motion, which is not the case for a pendulum's swinging movement.

The distance between two edges of a writing board is typically measured in centimeters. This is because the size of a writing board is usually small enough to be accurately measured in centimeters, as centimeters are more suitable for measuring such lengths compared to larger units like meters.

The other options are incorrect:
Option A: Meter is used for larger distances, not typically for measuring small objects like a writing board.
Option C: Millimeter is used for very small measurements, and the length of a writing board is usually too large for millimeter-scale measurement.
​​​​​​​Option D: Decimeter is a less common unit of length, and centimeters are typically used for everyday measurements of objects like writing boards.

In circular motion, the direction of motion changes continuously because the object is constantly moving along a curved path. Even if the speed (magnitude of velocity) remains constant, the direction of motion is always changing as the object moves along the circular path. This is why an object in circular motion experiences a centripetal force that constantly changes its direction toward the center of the circle.

The other options are incorrect:
Option A: The direction of motion does not remain fixed in circular motion; it changes as the object moves around the circle.
Option C: In circular motion, there is always acceleration (centripetal acceleration) because the direction of velocity changes, even if speed remains constant.
​​​​​​​Option D: Velocity is not constant in circular motion because velocity is a vector quantity that includes both speed and direction, and the direction is constantly changing.

Inertia is the property of a moving body that causes it to resist any change in its state of motion. Inertia means that an object will continue moving at a constant velocity in a straight line unless acted upon by an external force. This is why a moving body resists changes in its speed or direction.

The other options are incorrect:
Option A: Acceleration is the rate of change of velocity, but it is not what resists changes in motion. Inertia does.
Option B: Speed refers to how fast an object is moving, but it does not resist changes in motion. Inertia does.
Option D: Weight is the force exerted by gravity on an object and is related to mass but does not resist changes in motion. Inertia is responsible for that.

The motion of a train along a curved track on hills is an example of curvilinear motion, as the train moves along a curved path. Curvilinear motion occurs when an object moves along a curved trajectory, as seen in this example of a train navigating a curved track.

The other options are incorrect:
Option A: The motion of soldiers on march past is not periodic motion; it is a regular motion but does not repeat in a cyclical manner.
Option C: Not every periodic motion is oscillatory. For example, a satellite in orbit is periodic but not oscillatory, as it does not move back and forth.
Option D: The motion of a hockey player running after a ball is not combined motion; it is an example of linear motion. Combined motion occurs when multiple types of motion (like rotational and linear) occur together.

The motion of a vehicle on a straight road is rectilinear motion, as it involves movement along a straight line. Rectilinear motion is a type of motion where an object moves in a straight path, and this is exactly what happens when a vehicle moves along a straight road.

The other statements are correct:
Option B: The motion of honeybees is indeed an example of random motion, as their movement is unpredictable and erratic.
Option C: A cubit is historically the length of the forearm from the elbow to the tip of the middle finger.
Option D: Centigrade (or Celsius) is not the SI unit of temperature. The SI unit for temperature is Kelvin (K).

Motion is defined as the change in the position of an object with time. As an object moves, its position changes relative to a reference point, and this change occurs over a period of time.

The other options are incorrect:
Option A: Time and position are part of the correct definition, but the phrasing is not accurate.
Option C: Movement refers to the action itself, but motion is specifically the change in position over time.
Option D: This option is incorrect as option B is the correct answer.