Physics - Online Test
Q1. In which of the following cases is the net force zero
Answer : Option A
Explaination / Solution:
As no external fields like, electric,magnetic and gravitational field acting on electron the net force is zero
Q2. Hypothesis
Answer : Option D
Explaination / Solution:
In science, a hypothesis is an idea or explanation that you then test through study and experimentation.
Q3. when two capacitors are put in series, the equivalent capacitance is
Answer : Option C
Explaination / Solution:
When two capacitors C1 and C2 are connected in series, the reciprocal of the equivalent capacitance in series is equal to the sum of the reciprocals of the two individual capacitances.
It has value lesser than the least value of capacitance.
It has value lesser than the least value of capacitance.
Q4. A solid sphere of mass M and radius R spins about an axis passing through its centre making 600 rpm. Its kinetic energy of rotation is
Answer : Option B
Explaination / Solution:
Kinetic energy of rotation
K =
revolution per second
angular velocity rad/sec
moment of inertia about an axis passing through centre of solid sphere
Kinetic energy of rotation
Q5. According to Stokes’ law if η is the coefficient of viscosity, 'R' the radius of the sphere and it is moving with a velocity v the viscous drag force F is given by
Answer : Option B
Explaination / Solution:
The force of viscosity on a small sphere moving through a viscous fluid is given by:
Where:
- Fd is the frictional force – known as Stokes' drag – acting on the interface between the fluid and the particle
- η is the dynamic viscosity
- R is the radius of the spherical object
- v is the flow velocity relative to the object.
In SI units, Fd is given in Newtons, η in Pa·s, R in meters, and v in m/s.
Q6.
Molar volume is the volume occupied by 1 mol of any (ideal) gas at standard temperature and pressure (STP : 1 atmospheric pressure, 0 C). The value of Molar volume is
Answer : Option A
Explaination / Solution:
PV=nRT
V=nRTP=1×8.31×2731.01×105=0.02224m3=22.4lit
Q7. Accommodation of the human eye is
Answer : Option C
Explaination / Solution:
No Explaination.
Q8. α -rays are
Answer : Option D
Explaination / Solution:
Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus. They are generally produced in the process of alpha decay, but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α.
Q9. An AC voltage source of variable angular frequency 'w' and fixed amplitude V0 is connected in series with a capacitance C and an electric bulb of resistance R (inductance zero). When 'w' is increased:
Answer : Option D
Explaination / Solution:
in CR circuit, impedance
current
as increases, Z decreases. Hence the current i increases. Therefore, the bulb glows brighter.
Q10. In which mode of heat transfer no medium is required?
Answer : Option D
Explaination / Solution:
Heat transfer through radiation takes place in form of electromagnetic waves.
