Physics Syllabus (JEE Main)
Q. In a Wheatstone bridge, if the resistance R2 is doubled, what effect does it have on the balance condition?
A.
It remains balanced.
B.
It becomes unbalanced.
C.
It requires R4 to be halved.
D.
It requires R1 to be doubled.
Show solution
Solution
Doubling R2 will change the ratio R1/R2, thus unbalancing the bridge.
Correct Answer: B — It becomes unbalanced.
Learn More →
Q. In a Wheatstone bridge, if the resistance R4 is adjusted to achieve balance, what does this imply about the other resistances?
A.
They are equal.
B.
They are in series.
C.
They are in parallel.
D.
They maintain a specific ratio.
Show solution
Solution
Adjusting R4 to achieve balance implies that the other resistances maintain a specific ratio.
Correct Answer: D — They maintain a specific ratio.
Learn More →
Q. In a Wheatstone bridge, if the resistances are 1Ω, 2Ω, 3Ω, and 6Ω, is the bridge balanced?
A.
Yes
B.
No
C.
Only if R4 is adjusted
D.
Only if R3 is adjusted
Show solution
Solution
The bridge is not balanced because 1/2 is not equal to 3/6.
Correct Answer: B — No
Learn More →
Q. In a Wheatstone bridge, if the resistances are P = 5Ω, Q = 10Ω, R = 15Ω, what is the value of S for balance?
A.
7.5Ω
B.
10Ω
C.
12.5Ω
D.
15Ω
Show solution
Solution
Using the balance condition P/Q = R/S, we find S = (Q*R)/P = (10*15)/5 = 30Ω.
Correct Answer: C — 12.5Ω
Learn More →
Q. In a Wheatstone bridge, if the resistances are R1 = 2Ω, R2 = 3Ω, R3 = 4Ω, what is the value of R4 for balance?
A.
6Ω
B.
8Ω
C.
12Ω
D.
1.5Ω
Show solution
Solution
For balance, R4 must be 6Ω since 2/3 = 4/6.
Correct Answer: A — 6Ω
Learn More →
Q. In a Wheatstone bridge, if the supply voltage is 12V and the bridge is balanced, what is the voltage across each arm?
A.
6V each
B.
12V each
C.
4V each
D.
8V each
Show solution
Solution
In a balanced Wheatstone bridge, the voltage divides equally across the two arms, so each arm would have 6V if the total is 12V.
Correct Answer: A — 6V each
Learn More →
Q. In amplitude modulation (AM), what does the amplitude of the carrier wave represent?
A.
The frequency of the modulating signal
B.
The phase of the modulating signal
C.
The information signal
D.
The power of the carrier wave
Show solution
Solution
In AM, the amplitude of the carrier wave varies in accordance with the amplitude of the modulating signal, which carries the information.
Correct Answer: C — The information signal
Learn More →
Q. In amplitude modulation (AM), what does the carrier wave represent?
A.
The information signal
B.
The frequency of the modulated signal
C.
The average power of the signal
D.
The high-frequency signal that carries the information
Show solution
Solution
In AM, the carrier wave is a high-frequency signal that carries the information signal by varying its amplitude.
Correct Answer: D — The high-frequency signal that carries the information
Learn More →
Q. In an AC circuit, if the capacitive reactance is greater than the inductive reactance, the circuit is said to be:
A.
Resistive
B.
Inductive
C.
Capacitive
D.
Neutral
Show solution
Solution
If capacitive reactance (X_C) is greater than inductive reactance (X_L), the circuit is capacitive.
Correct Answer: C — Capacitive
Learn More →
Q. In an AC circuit, if the current lags the voltage by 30 degrees, what is the type of load?
A.
Resistive
B.
Inductive
C.
Capacitive
D.
None of the above
Show solution
Solution
If the current lags the voltage, it indicates an inductive load, as inductors cause the current to lag behind the voltage.
Correct Answer: B — Inductive
Learn More →
Q. In an AC circuit, if the current lags the voltage by 30 degrees, what type of circuit is it?
A.
Resistive
B.
Inductive
C.
Capacitive
D.
None of the above
Show solution
Solution
If the current lags the voltage, it indicates an inductive circuit, where the current phase is behind the voltage phase.
Correct Answer: B — Inductive
Learn More →
Q. In an AC circuit, if the current lags the voltage by 30 degrees, what type of load is present?
A.
Resistive
B.
Inductive
C.
Capacitive
D.
None of the above
Show solution
Solution
If the current lags the voltage, it indicates the presence of an inductive load, as inductors cause the current to lag behind the voltage.
Correct Answer: B — Inductive
Learn More →
Q. In an AC circuit, if the current lags the voltage by 45 degrees, what is the type of load?
A.
Resistive
B.
Inductive
C.
Capacitive
D.
None of the above
Show solution
Solution
If the current lags the voltage, it indicates an inductive load, as inductors cause the current to lag behind the voltage.
Correct Answer: B — Inductive
Learn More →
Q. In an AC circuit, if the frequency is doubled, what happens to the inductive reactance?
A.
It doubles
B.
It halves
C.
It remains the same
D.
It quadruples
Show solution
Solution
Inductive reactance (X_L) is given by X_L = 2πfL. If the frequency (f) is doubled, X_L also doubles.
Correct Answer: B — It halves
Learn More →
Q. In an AC circuit, if the frequency is doubled, what happens to the reactance of an inductor?
A.
Doubles
B.
Halves
C.
Remains the same
D.
Quadruples
Show solution
Solution
The reactance of an inductor is given by X_L = 2πfL. If frequency is doubled, reactance halves.
Correct Answer: B — Halves
Learn More →
Q. In an AC circuit, if the power factor is 0.5, what is the angle between voltage and current?
A.
30 degrees
B.
60 degrees
C.
90 degrees
D.
45 degrees
Show solution
Solution
The power factor is cos(θ). If PF = 0.5, then θ = cos^(-1)(0.5) = 60 degrees.
Correct Answer: B — 60 degrees
Learn More →
Q. In an AC circuit, if the power factor is 1, what type of load is present?
A.
Inductive
B.
Capacitive
C.
Resistive
D.
Reactive
Show solution
Solution
A power factor of 1 indicates a purely resistive load.
Correct Answer: C — Resistive
Learn More →
Q. In an AC circuit, if the voltage is given by V(t) = V_0 sin(ωt), what is the expression for the current through a resistor R?
A.
I(t) = (V_0/R) sin(ωt)
B.
I(t) = (V_0/R) cos(ωt)
C.
I(t) = (R/V_0) sin(ωt)
D.
I(t) = (R/V_0) cos(ωt)
Show solution
Solution
For a resistor, the current is in phase with the voltage. Therefore, I(t) = V(t)/R = (V_0/R) sin(ωt).
Correct Answer: A — I(t) = (V_0/R) sin(ωt)
Learn More →
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
Show solution
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
Learn More →
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
Show solution
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
Learn More →
Q. In an experiment, a student measures the mass of an object as 200 g with an uncertainty of ±5 g. What is the range of possible values for the mass?
A.
195 g to 205 g
B.
200 g to 210 g
C.
195 g to 210 g
D.
200 g to 205 g
Show solution
Solution
Range = Measured value ± Uncertainty = 200 g ± 5 g = 195 g to 205 g.
Correct Answer: A — 195 g to 205 g
Learn More →
Q. In an experiment, the length of a rod is measured as 12.0 m with an uncertainty of ±0.5 m. What is the total uncertainty if the length is used in a calculation involving multiplication by 3?
A.
±1.5 m
B.
±0.5 m
C.
±0.75 m
D.
±0.25 m
Show solution
Solution
Total uncertainty = 3 * (0.5 m) = ±1.5 m.
Correct Answer: A — ±1.5 m
Learn More →
Q. In an experiment, the mass of an object is measured as 5.0 kg with an uncertainty of ±0.2 kg. What is the absolute error?
A.
0.2 kg
B.
0.5 kg
C.
0.1 kg
D.
0.3 kg
Show solution
Solution
Absolute error is the uncertainty in the measurement, which is ±0.2 kg.
Correct Answer: A — 0.2 kg
Learn More →
Q. In an experiment, the measured value of a voltage is 12.0 V with an uncertainty of ±0.2 V. What is the maximum possible error?
A.
0.2 V
B.
0.1 V
C.
0.5 V
D.
0.0 V
Show solution
Solution
Maximum possible error is equal to the uncertainty, which is ±0.2 V.
Correct Answer: A — 0.2 V
Learn More →
Q. In an experiment, the voltage is measured as 12.0 V with an uncertainty of ±0.3 V. What is the absolute error in the voltage measurement?
A.
0.3 V
B.
0.25 V
C.
0.5 V
D.
0.1 V
Show solution
Solution
The absolute error is given as ±0.3 V.
Correct Answer: A — 0.3 V
Learn More →
Q. In an experiment, the voltage is measured as 12.0 V with an uncertainty of ±0.5 V. What is the absolute error in the voltage measurement?
A.
0.5 V
B.
0.05 V
C.
5 V
D.
1 V
Show solution
Solution
The absolute error is given directly as ±0.5 V.
Correct Answer: A — 0.5 V
Learn More →
Q. In an experiment, the voltage is measured as 12.0 V with an uncertainty of ±0.5 V. What is the maximum possible error in the voltage measurement?
A.
0.5 V
B.
0.25 V
C.
1 V
D.
0.1 V
Show solution
Solution
The maximum possible error is the absolute uncertainty, which is ±0.5 V.
Correct Answer: A — 0.5 V
Learn More →
Q. In an ideal gas, the average kinetic energy of a molecule is directly proportional to which of the following?
A.
Pressure
B.
Volume
C.
Temperature
D.
Number of molecules
Show solution
Solution
The average kinetic energy of a molecule in an ideal gas is directly proportional to the absolute temperature of the gas, given by the formula KE_avg = (3/2)kT.
Correct Answer: C — Temperature
Learn More →
Q. In an ideal gas, the average kinetic energy of a molecule is directly proportional to:
A.
Pressure
B.
Volume
C.
Temperature
D.
Density
Show solution
Solution
The average kinetic energy of a molecule in an ideal gas is directly proportional to the absolute temperature (T) of the gas.
Correct Answer: C — Temperature
Learn More →
Q. In an ideal gas, the mean free path is defined as the average distance a molecule travels between collisions. Which factor does NOT affect the mean free path?
A.
Temperature of the gas.
B.
Density of the gas.
C.
Size of the gas molecules.
D.
Color of the gas molecules.
Show solution
Solution
The mean free path is affected by temperature, density, and size of the molecules, but not by the color of the gas molecules.
Correct Answer: D — Color of the gas molecules.
Learn More →
Showing 2881 to 2910 of 5000 (167 Pages)