Q. In a double-slit experiment, if the light source is changed from monochromatic to polychromatic, what happens to the interference pattern? (2019)
A.
Pattern becomes sharper
B.
Pattern becomes broader
C.
Pattern disappears
D.
Pattern remains unchanged
Show solution
Solution
Using polychromatic light results in overlapping patterns of different wavelengths, causing the overall pattern to become broader.
Correct Answer:
B
— Pattern becomes broader
Learn More →
Q. In a double-slit experiment, if the screen is moved further away from the slits, what happens to the fringe separation? (2019)
A.
Increases
B.
Decreases
C.
Remains the same
D.
Becomes zero
Show solution
Solution
Moving the screen further away increases the fringe separation, as fringe width β = λD/d; increasing D increases β.
Correct Answer:
A
— Increases
Learn More →
Q. In a double-slit experiment, if the wavelength of light is halved, what happens to the fringe width? (2020)
A.
It doubles
B.
It halves
C.
It remains the same
D.
It quadruples
Show solution
Solution
Fringe width (β) is given by β = λD/d. If λ is halved, β will also be halved.
Correct Answer:
A
— It doubles
Learn More →
Q. In a first-order reaction, if the concentration of reactant decreases from 0.8 M to 0.2 M in 20 minutes, what is the rate constant? (2022)
A.
0.0347 min⁻¹
B.
0.0693 min⁻¹
C.
0.1 min⁻¹
D.
0.2 min⁻¹
Show solution
Solution
Using the first-order rate equation, k = (ln[A₀] - ln[A]) / t. Here, k = (ln(0.8) - ln(0.2)) / 20 = 0.0347 min⁻¹.
Correct Answer:
A
— 0.0347 min⁻¹
Learn More →
Q. In a first-order reaction, if the half-life is constant, what can be said about the rate constant? (2023)
A.
It increases with time
B.
It decreases with time
C.
It remains constant
D.
It is zero
Show solution
Solution
In a first-order reaction, the half-life is constant, which indicates that the rate constant remains constant.
Correct Answer:
C
— It remains constant
Learn More →
Q. In a first-order reaction, if the rate constant k is 0.03 min⁻¹, what is the time required for the concentration to decrease to half? (2020)
A.
23.1 min
B.
10.0 min
C.
20.0 min
D.
15.0 min
Show solution
Solution
t₁/₂ = 0.693 / k = 0.693 / 0.03 = 23.1 min.
Correct Answer:
A
— 23.1 min
Learn More →
Q. In a fluid at rest, the pressure at a point depends on which of the following? (2021)
A.
Depth of the fluid
B.
Shape of the container
C.
Volume of the fluid
D.
Temperature of the fluid
Show solution
Solution
In a fluid at rest, the pressure at a point depends on the depth of the fluid above that point.
Correct Answer:
A
— Depth of the fluid
Learn More →
Q. In a fluid at rest, the pressure at a point depends on:
A.
The height of the fluid column above it
B.
The shape of the container
C.
The volume of the fluid
D.
The temperature of the fluid
Show solution
Solution
In a fluid at rest, the pressure at a point depends on the height of the fluid column above it, as described by hydrostatic pressure.
Correct Answer:
A
— The height of the fluid column above it
Learn More →
Q. In a fluid flow, what does the term 'laminar flow' refer to? (2019)
A.
Flow with high turbulence.
B.
Flow in parallel layers.
C.
Flow with varying velocity.
D.
Flow that is compressible.
Show solution
Solution
Laminar flow refers to fluid motion in parallel layers with no disruption between them.
Correct Answer:
B
— Flow in parallel layers.
Learn More →
Q. In a fluid, what is the relationship between depth and pressure?
A.
Pressure increases with depth
B.
Pressure decreases with depth
C.
Pressure remains constant
D.
Pressure is independent of depth
Show solution
Solution
In a fluid, pressure increases with depth due to the weight of the fluid above.
Correct Answer:
A
— Pressure increases with depth
Learn More →
Q. In a fluid, what is the term for the height of a fluid column that exerts a certain pressure?
A.
Hydrostatic Height
B.
Fluid Column Height
C.
Hydrostatic Head
D.
Fluid Pressure Height
Show solution
Solution
Hydrostatic head is the height of a fluid column that exerts a certain pressure, calculated as pressure divided by the density and gravitational acceleration.
Correct Answer:
C
— Hydrostatic Head
Learn More →
Q. In a fluid, what is the term for the surface phenomenon that causes the surface to behave like a stretched elastic membrane?
A.
Viscosity
B.
Surface Tension
C.
Capillarity
D.
Hydrostatic Pressure
Show solution
Solution
Surface tension is the property of a fluid that causes its surface to behave like a stretched elastic membrane.
Correct Answer:
B
— Surface Tension
Learn More →
Q. In a food chain, which of the following is a primary consumer? (2019)
A.
Grass
B.
Rabbit
C.
Fox
D.
Eagle
Show solution
Solution
A rabbit is a primary consumer as it feeds on plants (producers).
Correct Answer:
B
— Rabbit
Learn More →
Q. In a food chain, which of the following is the correct order of energy flow? (2021)
A.
Producer → Consumer → Decomposer
B.
Consumer → Producer → Decomposer
C.
Decomposer → Producer → Consumer
D.
Producer → Decomposer → Consumer
Show solution
Solution
The correct order of energy flow in a food chain is Producer → Consumer → Decomposer.
Correct Answer:
A
— Producer → Consumer → Decomposer
Learn More →
Q. In a food chain, which of the following is the primary producer? (2019)
A.
Herbivores
B.
Carnivores
C.
Plants
D.
Decomposers
Show solution
Solution
Primary producers are organisms that produce their own food, primarily plants through photosynthesis.
Correct Answer:
C
— Plants
Learn More →
Q. In a galvanic cell, if the anode reaction is 2Ag⁺ + 2e⁻ → 2Ag, what is the cathode reaction? (2022)
A.
Cu²⁺ + 2e⁻ → Cu
B.
Zn²⁺ + 2e⁻ → Zn
C.
Fe²⁺ + 2e⁻ → Fe
D.
Pb²⁺ + 2e⁻ → Pb
Show solution
Solution
The cathode reaction must be a reduction reaction, and Cu²⁺ + 2e⁻ → Cu is a common cathode reaction.
Correct Answer:
A
— Cu²⁺ + 2e⁻ → Cu
Learn More →
Q. In a galvanic cell, if the anode reaction is 2H₂ → 4H⁺ + 4e⁻, what is the cathode reaction?
A.
O₂ + 4e⁻ + 4H⁺ → 2H₂O
B.
2H₂O + 4e⁻ → 2H₂ + O₂
C.
4H⁺ + 4e⁻ → 2H₂
D.
2H₂ + O₂ → 2H₂O
Show solution
Solution
The cathode reaction is O₂ + 4e⁻ + 4H⁺ → 2H₂O.
Correct Answer:
A
— O₂ + 4e⁻ + 4H⁺ → 2H₂O
Learn More →
Q. In a galvanic cell, if the anode reaction is Ag⁺ + e⁻ → Ag, what is the cathode reaction?
A.
Cu²⁺ + 2e⁻ → Cu
B.
Zn²⁺ + 2e⁻ → Zn
C.
Fe²⁺ + 2e⁻ → Fe
D.
Pb²⁺ + 2e⁻ → Pb
Show solution
Solution
The cathode reaction must be a reduction; Ag⁺ + e⁻ → Ag is the anode reaction.
Correct Answer:
A
— Cu²⁺ + 2e⁻ → Cu
Learn More →
Q. In a galvanic cell, if the anode reaction is Zn → Zn²⁺ + 2e⁻, what is the cathode reaction if the cathode is Cu²⁺ + 2e⁻ → Cu?
A.
Cu → Cu²⁺ + 2e⁻
B.
Zn²⁺ + 2e⁻ → Zn
C.
Zn + Cu²⁺ → Zn²⁺ + Cu
D.
Cu²⁺ + 2e⁻ → Cu
Show solution
Solution
The cathode reaction is Cu²⁺ + 2e⁻ → Cu.
Correct Answer:
D
— Cu²⁺ + 2e⁻ → Cu
Learn More →
Q. In a game, the probability of winning is 0.2. What is the probability of losing? (2019)
A.
0.2
B.
0.5
C.
0.8
D.
0.3
Show solution
Solution
The probability of losing is 1 - 0.2 = 0.8.
Correct Answer:
C
— 0.8
Learn More →
Q. In a generator, mechanical energy is converted into electrical energy through: (2019)
A.
Electromagnetic induction
B.
Thermal conduction
C.
Chemical reaction
D.
Nuclear fission
Show solution
Solution
In a generator, mechanical energy is converted into electrical energy through the process of electromagnetic induction.
Correct Answer:
A
— Electromagnetic induction
Learn More →
Q. In a generator, mechanical energy is converted into which type of energy? (2021)
A.
Thermal energy
B.
Chemical energy
C.
Electrical energy
D.
Nuclear energy
Show solution
Solution
In a generator, mechanical energy is converted into electrical energy through the process of electromagnetic induction.
Correct Answer:
C
— Electrical energy
Learn More →
Q. In a generator, what is the role of the rotating coil? (2022)
A.
To create a magnetic field
B.
To change the direction of current
C.
To induce EMF by changing magnetic flux
D.
To store electrical energy
Show solution
Solution
In a generator, the rotating coil induces EMF by changing the magnetic flux through it.
Correct Answer:
C
— To induce EMF by changing magnetic flux
Learn More →
Q. In a group of 50 people, 20 are smokers. What is the probability of selecting a non-smoker? (2022)
A.
2/5
B.
3/5
C.
1/2
D.
1/4
Show solution
Solution
Number of non-smokers = 50 - 20 = 30. Probability = 30/50 = 3/5.
Correct Answer:
B
— 3/5
Learn More →
Q. In a group of 50 people, 20 are smokers. What is the probability that a randomly selected person is a non-smoker? (2021)
A.
1/2
B.
3/5
C.
2/5
D.
1/5
Show solution
Solution
There are 50 - 20 = 30 non-smokers. The probability is 30/50 = 3/5.
Correct Answer:
B
— 3/5
Learn More →
Q. In a harmonic oscillator, if the mass is doubled while keeping the spring constant the same, how does the frequency change? (2021)
A.
Increases
B.
Decreases
C.
Remains the same
D.
Becomes zero
Show solution
Solution
Frequency (f) = (1/2π)√(k/m). If mass (m) is doubled, frequency decreases.
Correct Answer:
B
— Decreases
Learn More →
Q. In a heat engine, if the input heat is 500 J and the work done is 300 J, what is the efficiency? (2023) 2023
A.
60%
B.
50%
C.
40%
D.
70%
Show solution
Solution
Efficiency (η) = Work done / Input heat = 300 J / 500 J = 0.6 or 60%.
Correct Answer:
A
— 60%
Learn More →
Q. In a hexagonal close-packed (HCP) structure, how many atoms are present in one unit cell? (2023)
Show solution
Solution
In a hexagonal close-packed (HCP) structure, there are 6 atoms per unit cell.
Correct Answer:
C
— 6
Learn More →
Q. In a hexagonal close-packed (HCP) structure, what is the coordination number? (2022)
Show solution
Solution
In a hexagonal close-packed (HCP) structure, the coordination number is 12, as each atom is in contact with 12 others.
Correct Answer:
C
— 12
Learn More →
Q. In a lottery, there are 10 tickets, and 2 are winning tickets. What is the probability of picking a winning ticket?
A.
1/5
B.
1/10
C.
1/2
D.
2/10
Show solution
Solution
Probability = Number of winning tickets / Total tickets = 2/10 = 1/5.
Correct Answer:
A
— 1/5
Learn More →
Showing 1531 to 1560 of 5509 (184 Pages)
