TN 12TH PHYSICS - Online Test
Q1. Two coherent monochromatic light beams of intensities I and 4I are superposed. The maximum and minimum possible intensities in the resulting beam are
Answer : Option C
Explaination / Solution:
Imax
= I1 + I2 + 2√(I1I2)
=
I + 4I + 2√(4I2)
=
I + 4I + 4I = 9I
Imin
= I1 + I2 - 2√(I1I2)
=
I + 4I − 2√(4I2)
=
I + 4I − 4I = I
Q2. An electric dipole is
placed at an alignment angle of 30º with an electric field of 2 × 105
N C-1. It experiences a torque equal to 8 N m. The charge on the
dipole if the dipole length is 1 cm is
Answer : Option B
Explaination / Solution:
Q3. When a metallic surface is illuminated with radiation of wavelength λ, the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2λ, the stopping potential is V/4. The threshold wavelength for the metallic surface is
Answer : Option D
Explaination / Solution:
Q4. A carbon resistor of (47 ± 4.7 ) k Ω to be marked with rings of different colours for its identification. The colour code sequence will be
Answer : Option B
Explaination / Solution:
Q5. The ratio between the first three orbits of hydrogen atom is
Answer : Option C
Explaination / Solution:
The
radius of the nth orbit is rn
= n2r0
rn ∝ n2
r1:r2:r3 = 1:4:9
Q6. A circular coil of radius 5
cm and 50 turns carries a current of 3 ampere. The magnetic dipole moment of
the coil is
Answer : Option B
Explaination / Solution:
Q7. 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.
Q8. 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:
Q9. The method of making nanomaterial by assembling the atoms is called
Answer : Option A
Explaination / Solution:
No Explaination.
Q10. Which of the following are false for electromagnetic waves
Answer : Option C
Explaination / Solution:
No Explaination.
