Q. In a reaction, if the rate constant doubles when the temperature increases by 10°C, what is the activation energy (Ea) approximately?
A.
20 kJ/mol
B.
40 kJ/mol
C.
60 kJ/mol
D.
80 kJ/mol
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Solution
Using the Arrhenius equation, Ea can be estimated to be around 40 kJ/mol.
Correct Answer: B — 40 kJ/mol
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Q. In a redox reaction, which species is reduced?
A.
Oxidizing agent
B.
Reducing agent
C.
Product
D.
Reactant
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Solution
The oxidizing agent is the species that gains electrons and is reduced.
Correct Answer: A — Oxidizing agent
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Q. In a refrigerator, the work done on the system is used to:
A.
Increase the internal energy
B.
Decrease the internal energy
C.
Transfer heat from cold to hot
D.
Transfer heat from hot to cold
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Solution
In a refrigerator, work is done on the system to transfer heat from a colder body to a hotter body, which is against the natural flow of heat.
Correct Answer: C — Transfer heat from cold to hot
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Q. In a region of space where the electric field is uniform, what is the electric flux through a surface area A oriented perpendicular to the field?
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Solution
The electric flux Φ through a surface area A in a uniform electric field E is given by Φ = EA when the surface is perpendicular to the field.
Correct Answer: A — EA
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Q. In a region where the electric field is uniform, how does the electric flux through a surface depend on the angle between the field and the normal to the surface?
A.
It is maximum when the angle is 0°
B.
It is maximum when the angle is 90°
C.
It is independent of the angle
D.
It is zero when the angle is 0°
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Solution
The electric flux is maximum when the angle between the electric field and the normal to the surface is 0°, as Φ = E·A·cos(θ).
Correct Answer: A — It is maximum when the angle is 0°
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Q. In a region where the electric field is uniform, what is the shape of the Gaussian surface that would yield the simplest calculation of electric flux?
A.
Sphere
B.
Cube
C.
Cylinder
D.
Plane
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Solution
A plane is the simplest Gaussian surface for uniform electric fields, as it allows for straightforward calculation of flux.
Correct Answer: D — Plane
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Q. In a reversible process, the change in entropy of the universe is:
A.
Positive
B.
Negative
C.
Zero
D.
Undefined
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Solution
In a reversible process, the change in entropy of the universe is zero, as the system and surroundings are in equilibrium.
Correct Answer: C — Zero
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Q. In a reversible process, the change in Gibbs free energy (ΔG) is:
A.
Always positive
B.
Always negative
C.
Zero at equilibrium
D.
None of the above
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Solution
In a reversible process, the change in Gibbs free energy (ΔG) is zero at equilibrium.
Correct Answer: C — Zero at equilibrium
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Q. In a reversible process, the change in Gibbs free energy is equal to:
A.
Zero
B.
Enthalpy
C.
Entropy
D.
Temperature
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Solution
In a reversible process at equilibrium, the change in Gibbs free energy is zero.
Correct Answer: A — Zero
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Q. In a rotating system, if the angular momentum is doubled while the moment of inertia remains constant, what happens to the angular velocity?
A.
It doubles
B.
It halves
C.
It remains the same
D.
It quadruples
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Solution
Since L = Iω, if L is doubled and I remains constant, then ω must also double.
Correct Answer: A — It doubles
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Q. In a seesaw, if one child exerts a force of 30 N at a distance of 1.5 m from the pivot, what is the torque produced by this child?
A.
15 Nm
B.
30 Nm
C.
45 Nm
D.
60 Nm
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Solution
Torque (τ) = F × r = 30 N × 1.5 m = 45 Nm.
Correct Answer: C — 45 Nm
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Q. In a seesaw, if one child exerts a force of 30 N at a distance of 2 m from the pivot, what is the torque exerted by that child?
A.
15 Nm
B.
30 Nm
C.
60 Nm
D.
0 Nm
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Solution
Torque (τ) = F × r = 30 N × 2 m = 60 Nm.
Correct Answer: C — 60 Nm
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Q. In a seesaw, if one child exerts a torque of 30 N·m on one side, what torque must the other child exert to balance it?
A.
15 N·m
B.
30 N·m
C.
45 N·m
D.
60 N·m
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Solution
To balance the seesaw, the other child must exert an equal torque of 30 N·m.
Correct Answer: B — 30 N·m
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Q. In a semiconductor, what is the term for the energy required to move an electron from the valence band to the conduction band?
A.
Ionization energy
B.
Band gap energy
C.
Thermal energy
D.
Activation energy
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Solution
The energy required to move an electron from the valence band to the conduction band is known as the band gap energy.
Correct Answer: B — Band gap energy
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Q. In a sequence defined by a_n = 2^n, what is the 5th term?
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Solution
a_5 = 2^5 = 32.
Correct Answer: A — 16
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Q. In a sequence defined by a_n = 2^n, what is the value of a_5?
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Solution
a_5 = 2^5 = 32.
Correct Answer: A — 32
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Q. In a series circuit with a 12V battery and three resistors of 2Ω, 3Ω, and 5Ω, what is the current flowing through the circuit?
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Solution
Total resistance R = 2Ω + 3Ω + 5Ω = 10Ω. Current I = V / R = 12V / 10Ω = 1.2A.
Correct Answer: B — 2A
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Q. In a series circuit with a 12V battery and two resistors of 3Ω and 6Ω, what is the current flowing through the circuit?
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Solution
Total resistance R = R1 + R2 = 3Ω + 6Ω = 9Ω. Current I = V/R = 12V/9Ω = 4/3A.
Correct Answer: B — 2A
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Q. In a series circuit with a 12V battery and two resistors of 4Ω and 8Ω, what is the current flowing through the circuit?
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Solution
Total resistance R = R1 + R2 = 4Ω + 8Ω = 12Ω; I = V / R = 12V / 12Ω = 1A.
Correct Answer: B — 2A
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Q. In a series circuit, if one resistor fails (opens), what happens to the current in the circuit?
A.
It increases
B.
It decreases
C.
It becomes zero
D.
It remains the same
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Solution
In a series circuit, if one resistor fails, the circuit is broken and the current becomes zero.
Correct Answer: C — It becomes zero
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Q. In a series circuit, if one resistor fails open, what happens to the current in the circuit?
A.
It increases
B.
It decreases
C.
It becomes zero
D.
It remains the same
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Solution
In a series circuit, if one resistor fails open, the current becomes zero because the circuit is broken.
Correct Answer: C — It becomes zero
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Q. In a series circuit, if one resistor has a resistance of 5 Ω and another has 10 Ω, what is the total resistance?
A.
5 Ω
B.
10 Ω
C.
15 Ω
D.
20 Ω
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Solution
In a series circuit, total resistance R_total = R1 + R2 = 5 Ω + 10 Ω = 15 Ω.
Correct Answer: C — 15 Ω
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Q. In a series circuit, if one resistor has a resistivity of 5 Ω·m and another has 10 Ω·m, what is the total resistance?
A.
5 Ω
B.
10 Ω
C.
15 Ω
D.
20 Ω
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Solution
In series, total resistance R_total = R1 + R2 = 5 + 10 = 15 Ω.
Correct Answer: C — 15 Ω
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Q. In a series circuit, if one resistor is removed, what happens to the total resistance?
A.
It increases.
B.
It decreases.
C.
It remains the same.
D.
It becomes zero.
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Solution
In a series circuit, removing a resistor decreases the total resistance because the total resistance is the sum of all resistances.
Correct Answer: B — It decreases.
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Q. In a series RLC circuit, at resonance, what is the relationship between inductive reactance and capacitive reactance?
A.
X_L > X_C
B.
X_L < X_C
C.
X_L = X_C
D.
X_L + X_C = 0
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Solution
At resonance in a series RLC circuit, the inductive reactance (X_L) equals the capacitive reactance (X_C), hence X_L = X_C.
Correct Answer: C — X_L = X_C
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Q. In a series RLC circuit, if the resistance is increased, what happens to the bandwidth of the resonance?
A.
Increases
B.
Decreases
C.
Remains the same
D.
Becomes zero
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Solution
Increasing the resistance in a series RLC circuit decreases the bandwidth of the resonance because the quality factor (Q) is inversely proportional to resistance.
Correct Answer: B — Decreases
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Q. In a series RLC circuit, if the resistance is increased, what happens to the bandwidth?
A.
Increases
B.
Decreases
C.
Remains the same
D.
Becomes zero
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Solution
In a series RLC circuit, increasing the resistance decreases the bandwidth because the quality factor (Q) is inversely proportional to resistance.
Correct Answer: B — Decreases
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Q. In a series RLC circuit, if the resistance is increased, what happens to the bandwidth of the resonance peak?
A.
Increases
B.
Decreases
C.
Remains the same
D.
Becomes zero
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Solution
Increasing the resistance in a series RLC circuit decreases the bandwidth of the resonance peak.
Correct Answer: B — Decreases
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Q. In a series RLC circuit, what happens to the current at resonance?
A.
Maximum
B.
Minimum
C.
Zero
D.
Constant
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Solution
At resonance, the current is maximum in a series RLC circuit.
Correct Answer: A — Maximum
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Q. In a series RLC circuit, what happens to the current when the frequency is increased beyond the resonant frequency?
A.
Increases
B.
Decreases
C.
Remains constant
D.
Becomes zero
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Solution
Beyond the resonant frequency, the circuit becomes more inductive, causing the current to decrease.
Correct Answer: B — Decreases
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