Q. What happens to the viscosity of a liquid as temperature increases?
A.
Increases
B.
Decreases
C.
Remains constant
D.
Varies unpredictably
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Solution
As temperature increases, the viscosity of a liquid generally decreases because the increased thermal energy allows the molecules to move more freely.
Correct Answer: B — Decreases
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Q. What happens to the viscosity of gases with an increase in temperature?
A.
Increases
B.
Decreases
C.
Remains constant
D.
Varies randomly
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Solution
The viscosity of gases increases with an increase in temperature due to increased molecular motion.
Correct Answer: A — Increases
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Q. What happens to the voltage across a capacitor when it is fully charged?
A.
It becomes zero
B.
It equals the supply voltage
C.
It becomes negative
D.
It fluctuates
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Solution
When a capacitor is fully charged, the voltage across it equals the supply voltage.
Correct Answer: B — It equals the supply voltage
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Q. What happens to the volume of a gas if its temperature is increased at constant pressure?
A.
It decreases
B.
It increases
C.
It remains constant
D.
It becomes zero
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Solution
According to Charles's Law, at constant pressure, the volume of a gas increases with an increase in temperature.
Correct Answer: B — It increases
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Q. What happens to the volume of a gas when its temperature is increased at constant pressure?
A.
It decreases
B.
It increases
C.
It remains constant
D.
It becomes zero
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Solution
According to Charles's Law, the volume of a gas increases with an increase in temperature at constant pressure.
Correct Answer: B — It increases
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Q. What happens to the weight of an object when it is taken to a height equal to the radius of the Earth?
A.
It becomes zero
B.
It is halved
C.
It is doubled
D.
It remains the same
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Solution
At a height equal to the radius of the Earth, the weight is halved due to the inverse square law of gravitation.
Correct Answer: B — It is halved
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Q. What happens to the Young's modulus of a material as temperature increases?
A.
Increases
B.
Decreases
C.
Remains constant
D.
Becomes zero
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Solution
Generally, the Young's modulus of materials decreases with an increase in temperature.
Correct Answer: B — Decreases
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Q. What happens to the Young's modulus of a material when it is heated?
A.
It increases
B.
It decreases
C.
It remains constant
D.
It becomes zero
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Solution
Generally, the Young's modulus of a material decreases when it is heated due to increased atomic vibrations.
Correct Answer: B — It decreases
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Q. What is Brewster's angle for a medium with a refractive index of 1.5?
A.
30 degrees
B.
45 degrees
C.
60 degrees
D.
53 degrees
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Solution
Brewster's angle can be calculated using the formula tan(θ) = n, which gives approximately 53 degrees for n = 1.5.
Correct Answer: D — 53 degrees
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Q. What is Brewster's angle?
A.
The angle at which light is completely absorbed
B.
The angle at which light is reflected with maximum polarization
C.
The angle at which light refracts without any reflection
D.
The angle at which light travels fastest
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Solution
Brewster's angle is the angle of incidence at which light is reflected with maximum polarization.
Correct Answer: B — The angle at which light is reflected with maximum polarization
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A.
The direction of induced current opposes the change in magnetic flux
B.
The induced current flows in the same direction as the change in magnetic flux
C.
The induced EMF is always positive
D.
The magnetic field is always perpendicular to the current
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Solution
Lenz's law states that the direction of induced current is such that it opposes the change in magnetic flux that produced it.
Correct Answer: A — The direction of induced current opposes the change in magnetic flux
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Q. What is Poisson's ratio?
A.
Lateral strain/Longitudinal strain
B.
Longitudinal strain/Lateral strain
C.
Stress/Strain
D.
Strain/Stress
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Solution
Poisson's ratio (ν) is defined as the ratio of lateral strain to longitudinal strain.
Correct Answer: A — Lateral strain/Longitudinal strain
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Q. What is self-inductance?
A.
The ability of a coil to induce EMF in itself
B.
The ability of a coil to induce EMF in another coil
C.
The resistance of a coil to current flow
D.
The capacitance of a coil
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Solution
Self-inductance is the property of a coil to induce an EMF in itself due to a change in current.
Correct Answer: A — The ability of a coil to induce EMF in itself
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Q. What is self-induction?
A.
Induction of EMF in a coil due to its own changing current
B.
Induction of EMF in a coil due to an external magnetic field
C.
Induction of current in a conductor due to a magnetic field
D.
Induction of voltage in a capacitor
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Solution
Self-induction is the phenomenon where a changing current in a coil induces an EMF in the same coil.
Correct Answer: A — Induction of EMF in a coil due to its own changing current
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Q. What is surface tension?
A.
Force per unit length
B.
Energy per unit area
C.
Pressure difference
D.
Viscosity of a liquid
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Solution
Surface tension is defined as the force acting along the surface of a liquid per unit length.
Correct Answer: A — Force per unit length
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Q. What is the acceleration due to gravity at a height equal to the radius of the Earth?
A.
g/2
B.
g/3
C.
g/4
D.
g/5
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Solution
At height equal to radius, g' = g / (1 + h/R)² = g / (2)² = g/4.
Correct Answer: C — g/4
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Q. What is the acceleration of a rolling object down an incline if the incline angle is θ?
A.
g sin(θ)
B.
g sin(θ)/2
C.
g sin(θ)/3
D.
g sin(θ)/4
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Solution
The acceleration of a rolling object down an incline is given by g sin(θ)/2, considering both translational and rotational motion.
Correct Answer: B — g sin(θ)/2
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Q. What is the angle between the velocity vector and the acceleration vector of an object moving in uniform circular motion?
A.
0°
B.
45°
C.
90°
D.
180°
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Solution
In uniform circular motion, velocity is tangential and acceleration is radial, hence the angle is 90°.
Correct Answer: C — 90°
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Q. What is the angle of incidence at which light is completely polarized upon reflection?
A.
0 degrees
B.
45 degrees
C.
60 degrees
D.
Brewster's angle
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Solution
Light is completely polarized upon reflection at Brewster's angle, which is given by the formula tan(θ_B) = n2/n1.
Correct Answer: D — Brewster's angle
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Q. What is the angular momentum of a rolling object about its center of mass?
A.
mv
B.
Iω
C.
mv + Iω
D.
0
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Solution
The angular momentum L of a rolling object about its center of mass is given by L = mv + Iω, where I is the moment of inertia and ω is the angular velocity.
Correct Answer: C — mv + Iω
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Q. What is the angular velocity of a wheel rotating at 300 revolutions per minute?
A.
10π rad/s
B.
20π rad/s
C.
30π rad/s
D.
40π rad/s
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Solution
Angular velocity (ω) = 2π * (300/60) = 10π rad/s.
Correct Answer: B — 20π rad/s
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Q. What is the angular velocity of a wheel that makes 10 revolutions in 5 seconds?
A.
2π rad/s
B.
4π rad/s
C.
10π rad/s
D.
20π rad/s
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Solution
Angular velocity ω = θ/t = (10 * 2π rad) / 5 s = 4π rad/s.
Correct Answer: B — 4π rad/s
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Q. What is the approximate energy released in MeV during the fission of one uranium-235 nucleus?
A.
0.1 MeV
B.
1 MeV
C.
200 MeV
D.
1000 MeV
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Solution
The fission of one uranium-235 nucleus releases approximately 200 MeV of energy.
Correct Answer: C — 200 MeV
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Q. What is the average kinetic energy of a gas molecule at temperature T?
A.
(3/2)kT
B.
(1/2)kT
C.
(3/2)RT
D.
(1/2)RT
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Solution
The average kinetic energy of a gas molecule is given by the formula KE_avg = (3/2)kT, where k is the Boltzmann constant.
Correct Answer: A — (3/2)kT
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Q. What is the average kinetic energy of one mole of an ideal gas at temperature T?
A.
(3/2)RT
B.
(5/2)RT
C.
(1/2)RT
D.
(2/3)RT
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Solution
The average kinetic energy of one mole of an ideal gas is given by the formula KE = (3/2)RT, where R is the gas constant and T is the temperature in Kelvin.
Correct Answer: A — (3/2)RT
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Q. What is the average power consumed in an AC circuit with a power factor of 0.8 and an RMS voltage of 100 V with a current of 5 A?
A.
200 W
B.
400 W
C.
300 W
D.
500 W
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Solution
Average power (P) is given by P = V_rms * I_rms * PF. Therefore, P = 100 V * 5 A * 0.8 = 400 W.
Correct Answer: C — 300 W
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Q. What is the average power consumed in an AC circuit with a power factor of 0.8 and a maximum power of 100 W?
A.
80 W
B.
100 W
C.
120 W
D.
160 W
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Solution
Average power (P_avg) is given by P_avg = P_max × power factor. Therefore, P_avg = 100 W × 0.8 = 80 W.
Correct Answer: A — 80 W
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Q. What is the band gap energy of a typical semiconductor?
A.
0 eV
B.
1-3 eV
C.
5 eV
D.
10 eV
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Solution
Typical semiconductors have a band gap energy in the range of 1-3 eV.
Correct Answer: B — 1-3 eV
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Q. What is the band gap energy of a typical silicon semiconductor?
A.
0.1 eV
B.
1.1 eV
C.
2.0 eV
D.
3.5 eV
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Solution
Silicon has a band gap energy of approximately 1.1 eV, which is suitable for many electronic applications.
Correct Answer: B — 1.1 eV
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Q. What is the band gap energy of silicon at room temperature?
A.
0.1 eV
B.
1.1 eV
C.
2.0 eV
D.
3.5 eV
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Solution
The band gap energy of silicon at room temperature is approximately 1.1 eV.
Correct Answer: B — 1.1 eV
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