Physics - Online Test
Q1. If a half –wave rectified voltage is fed to a load resistor, which part of a cycle the load current will flow?
Answer : Option C
Explaination / Solution:
No Explaination.
Q2. When the current changes
from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The
co-efficient of self-induction of the coil is
Answer : Option D
Explaination / Solution:
Q3. The method of making nanomaterial by assembling the atoms is called
Answer : Option A
Explaination / Solution:
No Explaination.
Q4. Which of the following are false for electromagnetic waves
Answer : Option C
Explaination / Solution:
No Explaination.
Q5. If the velocity and wavelength of light in air
is Va and λa and that in water is Vw and λ ,
then the refractive index of water is,
Answer : Option B
Explaination / Solution:
n = speed of light in vacuum / speed of light in
medium =Va / Vw
Q6. When
light is incident on a soap film of thickness 5×10–5 cm, the
wavelength of light reflected maximum in the visible region is 5320 Å.
Refractive index of the film will be,
Answer : Option B
Explaination / Solution:
d
= 5 × 10-5
cm = 5 × 10-7
m
λ=5320
Å = 5.32 × 10-7 m
For
visible region n=2
μ=?
Q7. Four Gaussian surfaces are
given below with charges inside each Gaussian surface. Rank the electric flux
through each Gaussian surface in increasing order.
Answer : Option A
Explaination / Solution:
Q8. If a light of wavelength 330 nm is incident on a metal with work
function 3.55 eV, the electrons are emitted. Then the wavelength of the emitted
electron is (Take h = 6.6 × 10–34 Js)
Answer : Option B
Explaination / Solution:
Q9. What is the value of
resistance of the following resistor?
Answer : Option A
Explaination / Solution:
Q10. The charge of cathode rays is
Answer : Option B
Explaination / Solution:
Cathode ray is a beam of electrons
