CBSE 11TH PHYSICS - Online Test
Q1. With reference to figure the yield point corresponds to
Answer : Option D
Explaination / Solution:
No Explaination.
Q2. In Thermodynamics Extensive variables depend
Answer : Option D
Explaination / Solution:
The variables which depend on the size or amount of the substance are called extensive variables.
Example: Mass, volume etc
Q3. Proper framework for explaining microscopic phenomena is
Answer : Option C
Explaination / Solution:
Quantum mechanics (QM -- also known as quantum physics, or quantum theory) is a branch of physics which deals with physical phenomena at nanoscopic scales where the action is on the order of the Planck constant. It departs from classical mechanics primarily at the quantum realm of atomic and subatomic length scales.
Q4. According to Newton's third law of motion, the action and reaction forces are
Answer : Option A
Explaination / Solution:
When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.To every action there is always opposed an equal reaction or the mutual actions of two bodies upon each other are always equal and opposite in direction.
Q5. in laminar flow
Answer : Option C
Explaination / Solution:
laminar flow (or streamline flow) occurs when a fluid flows in parallel layers, with no disruption between the layers. At low velocities, the fluid tends to flow without lateral mixing, and adjacent layers slide past one another like playing cards.
Q6. The number of degrees of freedom a diatomic molecule is
Answer : Option B
Explaination / Solution:
Degrees of freedom of a system refers to the possible independent motions a system can have.
the total degrees of freedom describing the motion of a diatomic molecule is 5.
3 for translation and 2 for rotation
Q7. expansion of water is called anomalous because
Answer : Option B
Explaination / Solution:
Liquids expand on heating and contract on cooling at moderate temperatures. But water exhibits an exceptional behaviour. When it is heated from 0 ºC, it actually contracts rather than expanding, up to 4 ºC. The volume of water is minimum at 4 ºC. Beyond 4 ºC, water starts expanding.This behaviour of water between 0 ºC and 4 ºC is called anomalous expansion of water..
Q8. The relative error is given by
Answer : Option B
Explaination / Solution:
Relative Error or fractional error : It is defined as the ration of mean absolute error to the mean value of the measured quantity.
Q9. The total mechanical energy of a damped system is
Answer : Option B
Explaination / Solution:
The energy is dissipitaed as it decreases in the exponential form , making the amplitude to zero ultimately .
every pendulam in non ideal condition behaves like damped system, where damping force which is proportional to velocity is offered it by air resistance
the fig shows the damped motion
where the amplittude of the succesive oscillayion is damped by an exponential fuction of time
Q10. The acceleration due to gravity at a height h in terms of mass of earth and radius of the earth and gravitational constant G is
Answer : Option A
Explaination / Solution:
We know by Newton's law of gravitation, the force on the body of mass m, situated at height h to the surface of the earth of mass ME is given by:
-(1)
we also know F=mass X acceleration( here acceleration is acceleration due to gravity)
F=mg -(2)
Equating (i) & (ii), we get
