Physics - Online Test
Q1. Axioms are
Answer : Option A
Explaination / Solution:
An axiom or postulate is a statement that is taken to be true, to serve as a premise or starting point for further reasoning and arguments.
Q2. Correct formula for capacitance in terms of area A and distance d,of a parallel plate capacitor in vacuum is
Answer : Option D
Explaination / Solution:
The capacitance of a parallel plate capacitor is given by
Q3. For rolling motion without slipping the kinetic energy of the body is
Answer : Option D
Explaination / Solution:
Rolling motion without slipping involve both translation motion and rotation motion. Hence kinetic energy of body in rolling motion is the sum of both translation kinetic energy and rotational kinetic energy.
Q4. The coefficient of viscosity for a fluid is defined as the ratio of
Answer : Option D
Explaination / Solution:
The degree to which a fluid resists flow under an applied force, expressed as the ratio of the shearing stress to the velocity gradient. The coefficient of viscosity of liquids decreases as temperature increases because the bonds between molecules are weakened.
Q5. Estimate the fraction of molecular volume to the actual volume occupied by oxygen gas at STP. Take the diameter of an oxygen molecule to be 3Ao
Answer : Option C
Explaination / Solution:
Radius =
molecular volume of oxygen
Actual volume of oxygen at STP = 22400cm3
ratio of molercular volume to the actual volume =
Q6. The bluish color predominates in a clear sky,
Answer : Option A
Explaination / Solution:
No Explaination.
Q7. Radioactivity is the phenomenon in which
Answer : Option C
Explaination / Solution:
No Explaination.
Q8. A light bulb is rated at 50W for a 220 V supply. The resistance of the bulb, the peak voltage of the source and the rms current through the bulb are
Answer : Option B
Explaination / Solution:
Peak value of voltage
rms value of current
Q9. The latent heat of vaporization is.
Answer : Option B
Explaination / Solution:
Latent heat of vaporization is actually the total amount of enthalpy (a kind of energy/heat) necessary to accomplish a phase change for a liquid or gas at the boiling/condensation point. Phase changes are generally considered at constant pressure, rather than constant volume.
Q10. In a moving coil galvanometer the current through the coil produces a torque to turn the coil. The torque is balanced by
Answer : Option B
Explaination / Solution:
In a moving coil galvanometer, the coil is pivoted on a helical spring. When current passes through the coil, it experiences a torque and deflects. A restoring torque is set up in the helical spring which tries to restore the coil to its original position.
