MCQs

Explanation
A lever is a stiff bar that rests on a support called a fulcrum, which lifts or moves loads. The fulcrum is the point where the lever pivots , and it can be used to change the direction of a force or to gain a mechanical advantage, making it easier to lift or move heavy loads. Examples : Hammer, crow bar, a pair of pilers and seesaw.

Explanation
Lever, pulley, wedge, wheel, inclined plane, and screw are examples of simple machines. These are basic machines that change the direction or magnitude of a force, making it easier to lift, move, or apply force to an object. There are six types of simple machines : Inclined Plane Lever Wheel and Axle Pulley Wedge Screw

Explanation
The correct answer is: Simple machines magnify the force you use. This statement is true for many simple machines, such as levers, pulleys, and wheel and axle systems. Which are designed to multiply the force you apply, making it easier to lift, move, or apply force to an object.

Explanation
To find the speed, we can use the formula : Speed = Distance / Time Given: Distance = 150 meters Time = 5 seconds Speed = 150 / 5 Speed = 30 m/s So, the cycling speed of the girl is 30 meters per second.

Explanation
Force is the only option that can change an object's speed. According to Newton's second law of motion , force is directly related to an object's acceleration, which is the change in speed over time.

Explanation
Force cannot change the content of an object , as it only affects the object's motion, shape, and position, but not its composition or internal structure.

Explanation
Laboratory thermometers typically have a lower temperature range than clinical thermometers, and are designed to measure temperatures in a laboratory setting. The lowest temperature in a laboratory thermometer is often around -10°C or even lower , depending on the specific thermometer.

Explanation
When handling a clinical thermometer, you should: Wash it before use (to ensure cleanliness and accuracy) Stay at one place (to avoid moving around and potentially breaking the thermometer) Place it in a cover after use (to protect the thermometer from damage and contamination) But you should not Run while handling a clinical thermometer, as this could cause the thermometer to break or become damaged.

Explanation
A pulley system is commonly used to raise and lower flags. As it allows for a change in direction of the force and makes it easier to lift the flag to a higher position.

Explanation
A pulley is a simple machine that uses grooved wheels and a rope to raise, lower, or move a load. It changes the direction of the force, making it easier to lift or move heavy loads. Examples : Raising a load and A flag pulley.