Physics - Online Test
Q1. The sharpness of resonance is given by
Answer : Option B
Explaination / Solution:
Sharpness of resonance is quantitatively described by a dimensionless number known as Q-factor or quality factor which is numerically equal to ratio of resonant frequency to bandwidth.
therefore
Q-factor = resonant frequency / bandwidth
sharpness of resonance =
Q2. Which of the following is true about equipotential lines
Answer : Option B
Explaination / Solution:
The potential at all points on an equipotential surface is constant and work done in moving a charge on an equipotential surface is zero. Electric field lines show the direction of the electric field at the point. If the electric field lines were tangential, parallel or opposite to the equipotential surface, a tangential field will exist on the surface and work done in moving a charge on the surface is not zero. Therefore electric field lines are always perpendicular to the equipotential surface.
Q3. Analogue of mass in rotational motion is
Answer : Option B
Explaination / Solution:
The moment of inertia is a physical quantity which tells how easily a body can be rotated about a given axis. It is a rotational analogue of mass. It plays the same role in rotational motion as 'inertia' does in translational motion. Large moment of inertia also helps in keeping the rotation motion uniform.
Q4. According to Bernoulli’s equation for a varying cross-section pipe carrying incompressible liquid, pressure p, density ρ velocity v and height h at a place where acceleration due to gravity is g
Answer : Option B
Explaination / Solution:
According to conservation of enegy,
Total energy of any system is always conserved.
And Bernoulli's Theorem says that at any point of the pipe in which the liquid is flowing the sum of all the energies (Pressure Energy,Kinetic Energy,Potential Energy) is always constant.
Q5. The molar specific heat at constant volume, for monatomic gases is
Answer : Option B
Explaination / Solution:
for monatomic gases f = 3
Q6. Domestic power supply in India is
Answer : Option B
Explaination / Solution:
No Explaination.
Q7.
the binding energy of the nucleus is related to mass defect Δm by
Answer : Option D
Explaination / Solution:
This follows from the mass energy equivalence relation of the special theory of relativity, proposed by Einstein.
Q8. For an ideal gas the coefficient of volume expansion at constant pressure is
Answer : Option B
Explaination / Solution:
γ=ΔVVΔTPV=nRTV=nRTPPΔV=nRΔTΔV=nRΔTPγ=nRΔTPnRTP×1ΔT=nRΔTP×PnRT×1ΔT=1T
Q9. For two parallel wires carrying currents Ia and Ib seperated by a distance d, the magnitude of force acting on length L of any of the wires is
Answer : Option B
Explaination / Solution:
The conductor carrying current Ib is placed in the magnetic field created by the conductor carrying current . The force it experiences
Q10. When two quantities are added or subtracted, the absolute error in the final result is
Answer : Option C
Explaination / Solution:
When two quantities are added or subtracted, the absolute error in the final result is the sum of the absolute errors in the individual quantities.
e.g: error in the sum x=a+b is
maximum value of error =
