Q. In an AC circuit, the average power consumed is given by which formula? (2022)
A.
P = VI
B.
P = VI cos(φ)
C.
P = V²/R
D.
P = I²R
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Solution
The average power (P) consumed in an AC circuit is given by P = VI cos(φ), where φ is the phase angle between voltage and current.
Correct Answer: B — P = VI cos(φ)
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Q. In an AC circuit, the current lags behind the voltage by 90 degrees in which component? (2020)
A.
Resistor
B.
Capacitor
C.
Inductor
D.
Transformer
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Solution
In an inductor, the current lags behind the voltage by 90 degrees.
Correct Answer: C — Inductor
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Q. In an AC circuit, the current lags behind the voltage by 90 degrees in which type of circuit? (2020)
A.
Resistive
B.
Inductive
C.
Capacitive
D.
RLC
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Solution
In an inductive circuit, the current lags behind the voltage by 90 degrees.
Correct Answer: B — Inductive
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Q. In an AC circuit, the current lags the voltage by 90 degrees in which of the following components? (2020)
A.
Resistor
B.
Capacitor
C.
Inductor
D.
Transformer
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Solution
In an inductor, the current lags the voltage by 90 degrees.
Correct Answer: C — Inductor
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Q. In an AC circuit, the current lags the voltage by 90 degrees in which type of circuit? (2020)
A.
Resistive
B.
Capacitive
C.
Inductive
D.
RLC
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Solution
In an inductive circuit, the current lags the voltage by 90 degrees.
Correct Answer: C — Inductive
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Q. In an AC circuit, the voltage is given by V(t) = V0 sin(ωt). What is the peak voltage? (2021)
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Solution
The peak voltage in the equation V(t) = V0 sin(ωt) is V0.
Correct Answer: A — V0
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Q. In an AC circuit, the voltage is given by V(t) = V0 sin(ωt). What is the peak voltage if V0 = 10V? (2021)
A.
5V
B.
10V
C.
15V
D.
20V
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Solution
The peak voltage V0 is given directly in the equation as 10V.
Correct Answer: B — 10V
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Q. In an AC circuit, what is the phase difference between voltage and current in a purely inductive circuit? (2021)
A.
0 degrees
B.
90 degrees
C.
180 degrees
D.
270 degrees
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Solution
In a purely inductive AC circuit, the current lags the voltage by 90 degrees.
Correct Answer: B — 90 degrees
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Q. In an AC circuit, what is the relationship between the average power and the RMS voltage? (2023)
A.
P = V_rms²/R
B.
P = V_peak²/R
C.
P = V_rms/R
D.
P = V_peak/R
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Solution
The average power (P) in an AC circuit is given by P = V_rms²/R, where R is the resistance.
Correct Answer: A — P = V_rms²/R
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Q. In an AC circuit, what is the unit of reactance? (2019)
A.
Ohm
B.
Farad
C.
Henry
D.
Volt
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Solution
Reactance is measured in Ohms, just like resistance.
Correct Answer: A — Ohm
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Q. In an AC generator, the induced EMF is maximum when the coil is positioned at what angle to the magnetic field?
A.
0 degrees
B.
45 degrees
C.
90 degrees
D.
180 degrees
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Solution
In an AC generator, the induced EMF is maximum when the coil is positioned at 90 degrees to the magnetic field, as this is when the rate of change of magnetic flux is greatest.
Correct Answer: C — 90 degrees
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Q. In an adiabatic process, the relationship between pressure and volume for an ideal gas is given by which equation? (2020)
A.
PV^n = constant
B.
PV = nRT
C.
P1V1 = P2V2
D.
V/T = constant
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Solution
In an adiabatic process, the relationship is given by PV^n = constant, where n is the heat capacity ratio.
Correct Answer: A — PV^n = constant
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Q. In an adiabatic process, the temperature of a gas decreases. What happens to its pressure? (2021)
A.
Increases
B.
Decreases
C.
Remains constant
D.
Depends on volume
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Solution
In an adiabatic process, as the temperature decreases, the pressure also decreases due to the ideal gas law.
Correct Answer: B — Decreases
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Q. In an adiabatic process, the temperature of an ideal gas decreases. What happens to its pressure?
A.
Increases
B.
Decreases
C.
Remains constant
D.
Depends on volume
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Solution
In an adiabatic process, as the temperature decreases, the pressure also decreases due to the ideal gas law.
Correct Answer: B — Decreases
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Q. In an adiabatic process, which of the following is true? (2020)
A.
Heat is absorbed from the surroundings
B.
Heat is released to the surroundings
C.
No heat is exchanged
D.
Temperature remains constant
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Solution
In an adiabatic process, there is no heat exchange with the surroundings, meaning no heat is absorbed or released.
Correct Answer: C — No heat is exchanged
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Q. In an adiabatic process, which of the following remains constant? (2020)
A.
Temperature
B.
Pressure
C.
Internal Energy
D.
Enthalpy
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Solution
In an adiabatic process, there is no heat exchange, so the internal energy remains constant for an ideal gas.
Correct Answer: C — Internal Energy
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Q. In an analogy, which of the following best represents resistance in an electrical circuit? (2022)
A.
A narrow pipe
B.
A wide pipe
C.
A water tank
D.
A water wheel
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Solution
Resistance in an electrical circuit is analogous to a narrow pipe that restricts the flow of water.
Correct Answer: A — A narrow pipe
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Q. In an arithmetic progression, if the 3rd term is 15 and the 6th term is 24, what is the common difference?
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Solution
Let the first term be a and the common difference be d. From the equations a + 2d = 15 and a + 5d = 24, we can solve for d, which gives d = 3.
Correct Answer: B — 4
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Q. In an arithmetic progression, if the 4th term is 20 and the 7th term is 26, what is the first term?
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Solution
Let the first term be a and the common difference be d. From the equations a + 3d = 20 and a + 6d = 26, we can solve for a and find it to be 12.
Correct Answer: B — 12
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Q. In an arithmetic progression, if the 5th term is 20 and the 10th term is 35, what is the first term?
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Solution
Let the first term be a and the common difference be d. From the given terms, we have a + 4d = 20 and a + 9d = 35. Solving these gives a = 10.
Correct Answer: B — 10
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Q. In an arithmetic progression, if the first term is 12 and the last term is 48, and there are 10 terms, what is the common difference?
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Solution
Using the formula for the last term, 48 = 12 + (10-1)d. Solving gives d = 4.
Correct Answer: A — 4
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Q. In an arithmetic progression, if the first term is 5 and the common difference is 3, what is the 10th term?
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Solution
The nth term of an AP is given by a + (n-1)d. Here, a = 5, d = 3, and n = 10. So, the 10th term = 5 + (10-1) * 3 = 5 + 27 = 32.
Correct Answer: A — 32
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Q. In an arithmetic progression, if the sum of the first 10 terms is 250, what is the first term if the common difference is 5?
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Solution
Using the formula S_n = n/2 * (2a + (n-1)d), we can substitute n = 10 and d = 5 to find a = 20.
Correct Answer: B — 20
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Q. In an arithmetic series, if the first term is 5 and the last term is 45, and there are 10 terms, what is the common difference?
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Solution
Using the formula for the nth term: a_n = a + (n-1)d, we have 45 = 5 + 9d. Solving gives d = 4.
Correct Answer: A — 4
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Q. In an ecosystem, which of the following organisms is known as a primary consumer? (2019)
A.
Herbivores
B.
Carnivores
C.
Decomposers
D.
Producers
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Solution
Herbivores are primary consumers as they feed directly on producers (plants).
Correct Answer: A — Herbivores
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Q. In an ecosystem, which of the following organisms is known as a primary producer? (2021)
A.
Herbivores
B.
Carnivores
C.
Decomposers
D.
Plants
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Solution
Plants are primary producers as they convert sunlight into chemical energy through photosynthesis.
Correct Answer: D — Plants
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Q. In an electric circuit, if the voltage is 12 V and the current is 3 A, what is the power?
A.
36 W
B.
9 W
C.
4 W
D.
12 W
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Solution
Power in an electric circuit is given by P = V * I. Here, P = 12 V * 3 A = 36 W.
Correct Answer: A — 36 W
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Q. In an electric circuit, if the voltage is doubled while the resistance remains constant, what happens to the power?
A.
It remains the same
B.
It doubles
C.
It quadruples
D.
It halves
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Solution
Power in an electric circuit is given by P = V^2/R. If V is doubled, P becomes (2V)^2/R = 4V^2/R, which is quadrupled.
Correct Answer: C — It quadruples
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Q. In an electrochemical cell, the anode is where: (2019)
A.
Oxidation occurs
B.
Reduction occurs
C.
Electrons are gained
D.
Ions are produced
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Solution
In an electrochemical cell, oxidation occurs at the anode.
Correct Answer: A — Oxidation occurs
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Q. In an endothermic reaction, the enthalpy of the products is ____ than that of the reactants.
A.
higher
B.
lower
C.
equal
D.
unpredictable
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Solution
In an endothermic reaction, the enthalpy of the products is higher than that of the reactants.
Correct Answer: A — higher
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