1.
A person sitting in a moving bus suddenly moves forward when the bus suddenly stops.
Correct Answer
A. Due to inertia
Explanation
The person sitting in the moving bus suddenly moves forward when the bus suddenly stops due to inertia. Inertia is the tendency of an object to resist changes in its state of motion. When the bus stops suddenly, the person's body still wants to keep moving forward at the same speed as the bus. As a result, the person continues to move forward until an external force (such as the seatbelt or friction) acts upon them to bring them to a stop. The force exerted by the machine or the brakes are not the direct causes of the person's forward movement.
2.
A person sitting in a moving car has _________energy.
Correct Answer
C. Both kinetic and potential energy
Explanation
When a person is sitting in a moving car, they have both kinetic and potential energy. Kinetic energy is the energy of motion, which the person possesses due to the car's movement. Potential energy, on the other hand, is the energy that an object possesses due to its position or condition. In this case, the person has potential energy due to their position in the car, such as being elevated or being in a compressed or stretched state.
3.
Why does mud fly off a stick when you swing it into another object?
Correct Answer
B. Due to inertia
Explanation
When hitting another object with a stick, mud flies away due to inertia. Inertia is the tendency of an object to resist changes in its motion. When the stick hits the object, the mud particles initially at rest on the carpet try to remain at rest due to inertia. However, the force applied by the stick overcomes this inertia, causing the mud to be pushed away from the object.
4.
Why are transition elements given that name? Choose the most appropriate option.
Correct Answer
E. Both A and B
Explanation
Transition elements, also known as transition metals, are characterized by their variable valency or the ability to form ions with different charges depending on their chemical reactions. This variability in valency is due to the presence of partially filled d-orbitals, allowing these elements to readily lose or gain electrons. Additionally, many transition metals exhibit distinct colors when they form compounds, making them visually distinctive and contributing to their name as transition elements.
5.
Why is it challenging to prepare a supersaturated solution?
Correct Answer
A. Because it cant be prepared at room temperature
Explanation
Preparing a supersaturated solution is challenging because it cannot be achieved at room temperature. This is because, at higher temperatures, solutes dissolve more easily in solvents, allowing for a higher concentration of solute in the solution. However, when the solution cools down, the excess solute may not fully precipitate, resulting in a supersaturated solution. Therefore, it is difficult to prepare a supersaturated solution without manipulating temperature or other factors.
6.
Is electrolysis the same as ionization? If not, why?
Correct Answer
B. Electrolysis can't be done without ionization.
Explanation
Electrolysis and ionization are not the same because electrolysis requires ionization to occur. During electrolysis, an electric current is passed through a substance, causing it to split up into its ions. This process cannot happen without ionization, which is the formation of ions by gaining or losing electrons. Therefore, electrolysis and ionization are interconnected, with ionization being a necessary step for electrolysis to take place.
7.
Why on hitting the ball with the center of the bat more effective short is played?
Correct Answer
D. Both A and B
Explanation
Hitting the ball with the center of the bat is more effective when playing a shot due to two key factors. Firstly, it minimizes off-center forces, ensuring a straight and controlled trajectory by maintaining a net force of zero (fx + fy = 0). Secondly, striking the ball from the center helps maintain balance as the center of gravity remains within the base, enhancing the player's control and preventing loss of balance during the shot. In essence, the combination of minimizing off-center forces and maintaining balance contributes to the overall effectiveness of playing a shot with the center of the bat.
8.
Work is a
Correct Answer
A. Scalar Quantity
Explanation
Work is a scalar quantity because it only depends on the magnitude of the force applied and the displacement of the object in the direction of the force. It does not depend on the direction of the force or displacement. Scalar quantities are described by a magnitude only, while vector quantities have both magnitude and direction. Since work does not have a directional component, it is classified as a scalar quantity.
9.
What are Jacobson's organs?
Correct Answer
A. Two pits present on the palate of the snake
Explanation
Jacobson's organs are two pits located on the palate of a snake. These pits contain sensory cells that are sensitive to heat and help the snake detect prey and predators. The pits are connected to the snake's Jacobson's organ, which is responsible for processing the chemical signals from the environment. This unique organ allows snakes to navigate and locate prey even in the dark or when hidden.
10.
Each rank of classification is called:
Correct Answer
B. Evolutionary taxonomy
Explanation
Evolutionary taxonomy refers to the hierarchical system used to classify organisms based on their evolutionary relationships. It takes into account the shared characteristics and ancestry of different species to determine their placement in the classification hierarchy. This approach acknowledges that species evolve over time and aims to reflect their evolutionary history accurately.
11.
Enthalpy of products of exothermic reaction is_________.
Correct Answer
A. Lower
Explanation
In an exothermic reaction, the reactants release energy in the form of heat to the surroundings, resulting in a decrease in enthalpy. Therefore, the enthalpy of the products is less than that of the reactants.
12.
A cream separator works on the principle of
Correct Answer
A. Centrifugal Force
Explanation
A cream separator works on the principle of centrifugal force. Centrifugal force is the apparent force that acts outward on a body moving in a curved path. In the case of a cream separator, the mixture of milk and cream is spun rapidly in a circular motion. Due to the centrifugal force, the heavier milk particles are pushed toward the outer edge of the separator, while the lighter cream particles move towards the center. This separation allows for the extraction of cream from milk.