CBSE 11TH PHYSICS - Online Test
Q1. With reference to figure the tensile stress corresponds to stress at point
Answer : Option B
Explaination / Solution:
The point D on the graph is the ultimate tensile strength of the material. Beyond this point , additional strain is produced even by a reduced applied force and fracture occurs at point E.
After point D thinning of wire started and finally the wire breaks.
So D shows tensile strength.
Q2. The basic laws of physics are universal means
Answer : Option C
Explaination / Solution:
Laws of nature as expressed in physics as laws and theories are often said to be universal. This means that, so far as we have been able to test them, they apply everywhere and at every time, past, present and future.
Q3. When bodies are in contact with each other then
Answer : Option A
Explaination / Solution:
according to newton's third law of motion for every action there is always equal and opposite reaction or the mutual actions of two bodies upon each other. Whenever two objects interact with each other, then the pair of forces acting on them are equal in magnitude and opposite in direction.
Contact forces are mutual forces (action and reaction)
Q4. 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.
Q5. 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.
Q6. The molar specific heat at constant volume, for monatomic gases is
Answer : Option B
Explaination / Solution:
for monatomic gases f = 3
Q7. 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
Q8. 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 =
Q9. In simple harmonic motion the damping force is
Answer : Option C
Explaination / Solution:
In real oscillators, friction, or damping, slows the motion of the system. Due to frictional force, the velocity decreases in proportion to the acting frictional force.
where the c is the damping constant
Q10. Escape speed from the earth is the
Answer : Option A
Explaination / Solution:
The escape velocity is the minimum velocity required to leave a planet or moon. For a rocket or other object to leave a planet, it must overcome the pull of gravity.
Vescape=11184 m/sec approximate to 11.2 km/sec
