Q. In a predator-prey relationship, which of the following is true? (2022)
A.
Predators are always larger than their prey.
B.
Prey populations are always larger than predator populations.
C.
Predators help control prey populations.
D.
Prey can never escape predators.
Show solution
Solution
Predators help control the population of prey species, maintaining a balance in the ecosystem.
Correct Answer:
C
— Predators help control prey populations.
Learn More →
Q. In a ray diagram for a concave lens, the rays parallel to the principal axis appear to diverge from which point? (2021)
A.
Focal point
B.
Center of curvature
C.
Optical center
D.
Principal focus
Show solution
Solution
In a ray diagram for a concave lens, rays parallel to the principal axis appear to diverge from the focal point.
Correct Answer:
A
— Focal point
Learn More →
Q. In a reaction at equilibrium, if the concentration of a reactant is increased, what will happen to the equilibrium position? (2019)
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Depends on temperature
Show solution
Solution
Increasing the concentration of a reactant will shift the equilibrium position to the right, favoring the formation of products.
Correct Answer:
A
— Shift to the right
Learn More →
Q. In a reaction at equilibrium, if the concentration of products is increased, what will happen? (2022)
A.
Equilibrium shifts to the left
B.
Equilibrium shifts to the right
C.
No change
D.
Reaction stops
Show solution
Solution
According to Le Chatelier's principle, increasing the concentration of products will shift the equilibrium to the left, favoring the formation of reactants.
Correct Answer:
A
— Equilibrium shifts to the left
Learn More →
Q. In a reaction at equilibrium, if the concentration of reactants is increased, what will happen to the position of equilibrium? (2022)
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Depends on temperature
Show solution
Solution
According to Le Chatelier's principle, increasing the concentration of reactants will shift the equilibrium position to the right to produce more products.
Correct Answer:
A
— Shift to the right
Learn More →
Q. In a reaction at equilibrium, if the concentration of reactants is increased, what will happen? (2022)
A.
The equilibrium will shift to the right.
B.
The equilibrium will shift to the left.
C.
The equilibrium will not change.
D.
The reaction will stop.
Show solution
Solution
According to Le Chatelier's principle, if the concentration of reactants is increased, the equilibrium will shift to the right to produce more products.
Correct Answer:
A
— The equilibrium will shift to the right.
Learn More →
Q. In a reaction at equilibrium, if the temperature is increased and the reaction is exothermic, what will happen? (2021)
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Increase in Kc
Show solution
Solution
For an exothermic reaction, increasing the temperature shifts the equilibrium to the left, favoring the reactants.
Correct Answer:
B
— Shift to the left
Learn More →
Q. In a reaction at equilibrium, if the temperature is increased for an exothermic reaction, what will happen? (2022)
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Increase in pressure
Show solution
Solution
For an exothermic reaction, increasing the temperature shifts the equilibrium to the left, favoring the reactants.
Correct Answer:
B
— Shift to the left
Learn More →
Q. In a reaction mechanism, what is the term for the slowest step that determines the overall rate of the reaction? (2019)
A.
Intermediate
B.
Rate-determining step
C.
Catalyst
D.
Transition state
Show solution
Solution
The slowest step in a reaction mechanism that determines the overall rate of the reaction is called the rate-determining step.
Correct Answer:
B
— Rate-determining step
Learn More →
Q. In a reaction, if the concentration of reactants is doubled, what happens to the rate of reaction if it is first order? (2023)
A.
Doubles
B.
Triples
C.
Quadruples
D.
Remains the same
Show solution
Solution
For a first-order reaction, the rate is directly proportional to the concentration of the reactant, so doubling the concentration doubles the rate.
Correct Answer:
A
— Doubles
Learn More →
Q. In a reaction, if the concentration of reactants is doubled, what happens to the rate of reaction if the reaction is first order? (2023)
A.
Doubles
B.
Triples
C.
Quadruples
D.
Remains the same
Show solution
Solution
For a first-order reaction, the rate is directly proportional to the concentration of reactants, so doubling the concentration doubles the rate.
Correct Answer:
A
— Doubles
Learn More →
Q. In a redox reaction, if the oxidation number of an element increases, what happens to that element? (2020)
A.
It is oxidized
B.
It is reduced
C.
It remains unchanged
D.
It forms a compound
Show solution
Solution
An increase in oxidation number indicates that the element is losing electrons, which means it is being oxidized.
Correct Answer:
A
— It is oxidized
Learn More →
Q. In a redox reaction, if the oxidation state of an element decreases, what happens to that element? (2021)
A.
It is oxidized
B.
It is reduced
C.
It remains unchanged
D.
It is ionized
Show solution
Solution
A decrease in oxidation state indicates that the element has gained electrons, which means it is reduced.
Correct Answer:
B
— It is reduced
Learn More →
Q. In a redox reaction, if the oxidation state of an element decreases, what has occurred? (2021)
A.
Oxidation
B.
Reduction
C.
Neutralization
D.
Decomposition
Show solution
Solution
A decrease in oxidation state indicates that the element has gained electrons, which is defined as reduction.
Correct Answer:
B
— Reduction
Learn More →
Q. In a redox reaction, if the oxidation state of an element decreases, what is happening to that element? (2021)
A.
It is being oxidized
B.
It is being reduced
C.
It is unchanged
D.
It is ionized
Show solution
Solution
A decrease in oxidation state indicates that the element is gaining electrons, which means it is being reduced.
Correct Answer:
B
— It is being reduced
Learn More →
Q. In a redox reaction, if the oxidation state of an element decreases, what is it undergoing? (2021)
A.
Oxidation
B.
Reduction
C.
Neutralization
D.
Decomposition
Show solution
Solution
If the oxidation state of an element decreases, it is gaining electrons, which is known as reduction.
Correct Answer:
B
— Reduction
Learn More →
Q. In a redox reaction, if the oxidation state of an element increases, what happens to that element? (2021)
A.
It is oxidized
B.
It is reduced
C.
It remains unchanged
D.
It forms a compound
Show solution
Solution
An increase in the oxidation state of an element indicates that it has lost electrons, which means it is oxidized.
Correct Answer:
A
— It is oxidized
Learn More →
Q. In a redox reaction, the substance that gains electrons is called: (2021)
A.
Oxidizing agent
B.
Reducing agent
C.
Reducing agent
D.
None of the above
Show solution
Solution
The substance that gains electrons in a redox reaction is called the oxidizing agent.
Correct Answer:
A
— Oxidizing agent
Learn More →
Q. In a redox reaction, what happens to the oxidation state of the reducing agent? (2021)
A.
Increases
B.
Decreases
C.
Remains the same
D.
Varies
Show solution
Solution
The oxidation state of the reducing agent decreases as it loses electrons during the reaction.
Correct Answer:
B
— Decreases
Learn More →
Q. In a redox reaction, which of the following statements is true? (2020)
A.
Oxidation involves gain of electrons
B.
Reduction involves loss of electrons
C.
Oxidation state of an element decreases during oxidation
D.
Reduction involves gain of electrons
Show solution
Solution
Reduction is defined as the gain of electrons, which decreases the oxidation state of the element.
Correct Answer:
D
— Reduction involves gain of electrons
Learn More →
Q. In a reversible process, the work done is: (2023)
A.
Always maximum
B.
Always minimum
C.
Equal to the heat absorbed
D.
Independent of the path
Show solution
Solution
In a reversible process, the work done is always maximum compared to irreversible processes.
Correct Answer:
A
— Always maximum
Learn More →
Q. In a reversible reaction at equilibrium, if the concentration of reactants is increased, what will happen to the equilibrium position? (2023)
A.
Shift to the right
B.
Shift to the left
C.
No change
D.
Depends on temperature
Show solution
Solution
According to Le Chatelier's principle, increasing the concentration of reactants will shift the equilibrium position to the right, favoring the formation of products.
Correct Answer:
A
— Shift to the right
Learn More →
Q. In a reversible reaction at equilibrium, what happens if the temperature is increased? (2019)
A.
The reaction shifts to the exothermic side
B.
The reaction shifts to the endothermic side
C.
No change occurs
D.
The reaction rate decreases
Show solution
Solution
Increasing the temperature of an exothermic reaction shifts the equilibrium to the left (towards the reactants), while for an endothermic reaction, it shifts to the right (towards the products).
Correct Answer:
B
— The reaction shifts to the endothermic side
Learn More →
Q. In a reversible reaction, if the forward reaction is exothermic, what can be said about the reverse reaction? (2022)
A.
It is also exothermic
B.
It is endothermic
C.
It has no effect on equilibrium
D.
It is spontaneous
Show solution
Solution
If the forward reaction is exothermic, the reverse reaction must be endothermic, as it absorbs heat.
Correct Answer:
B
— It is endothermic
Learn More →
Q. In a semiconductor, what happens to the conductivity as temperature increases? (2021)
A.
Decreases
B.
Increases
C.
Remains constant
D.
Becomes zero
Show solution
Solution
The conductivity of a semiconductor increases with temperature due to more charge carriers being available.
Correct Answer:
B
— Increases
Learn More →
Q. In a series circuit with a 12V battery and two resistors of 4Ω and 8Ω, what is the voltage across the 8Ω resistor? (2022)
Show solution
Solution
Total resistance R_total = 4Ω + 8Ω = 12Ω. Current I = V/R_total = 12V/12Ω = 1A. Voltage across 8Ω = I * R = 1A * 8Ω = 8V.
Correct Answer:
B
— 6V
Learn More →
Q. In a series circuit with a 9V battery and three resistors of 1Ω, 2Ω, and 3Ω, what is the total resistance? (2019)
Show solution
Solution
Total resistance in series is R_total = R1 + R2 + R3 = 1 + 2 + 3 = 6Ω.
Correct Answer:
A
— 6Ω
Learn More →
Q. In a series circuit, if one resistor fails, what happens to the current in the circuit? (2019)
A.
It increases
B.
It decreases
C.
It stops
D.
It remains the same
Show solution
Solution
In a series circuit, if one resistor fails, the circuit is broken and the current stops.
Correct Answer:
C
— It stops
Learn More →
Q. In a series circuit, if one resistor is removed, what happens to the current? (2023)
A.
It increases
B.
It decreases
C.
It remains the same
D.
It becomes zero
Show solution
Solution
In a series circuit, removing one resistor breaks the circuit, causing the current to become zero.
Correct Answer:
D
— It becomes zero
Learn More →
Q. In a series circuit, if the resistance is doubled, what happens to the current flowing through the circuit? (2021)
A.
It doubles
B.
It halves
C.
It remains the same
D.
It becomes zero
Show solution
Solution
According to Ohm's law, I = V/R. If R is doubled, the current I will be halved for a constant voltage V.
Correct Answer:
B
— It halves
Learn More →
Showing 391 to 420 of 2979 (100 Pages)