Physics - Online Test
Q1. Two radiations with photon energies 0.9 eV and 3.3 eV respectively are falling on a metallic surface successively. If the work function of the metal is 0.6 eV, then the ratio of maximum speeds of emitted electrons will be
Answer : Option B
Explaination / Solution:
Q2. In India electricity is
supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the
resistance of a 60W bulb for use in India is R, the resistance of a 60W bulb
for use in USA will be
Answer : Option C
Explaination / Solution:
Q3. The electric potential between a proton and an
electron is given by V=V0ln ( r/r0 ) , where r0
is a constant. Assume that Bohr atom model is applicable to potential, then
variation of radius of nth orbit rn with the principal quantum
number n is
Answer : Option B
Explaination / Solution:
It
provide the centripetal force.
Q4.
A wire of length l carries a current I along the Y
direction and magnetic field is given by
The magnitude of Lorentz force acting on the
wire is
Answer : Option A
Explaination / Solution:
Q5. When a transistor is fully switched on, it is said to be
Answer : Option B
Explaination / Solution:
No Explaination.
Q6. A step-down transformer reduces the supply voltage from 220 V to 11 V and increase the current from 6 A to 100 A. Then its efficiency is
Answer : Option B
Explaination / Solution:
Q7. The technology used for stopping the brain from processing pain is
Answer : Option C
Explaination / Solution:
No Explaination.
Q8. During the propagation of electromagnetic waves in a medium:
Answer : Option C
Explaination / Solution:
No Explaination.
Q9. An air bubble in glass slab of refractive index 1.5 (near normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness of the slab is,
Answer : Option C
Explaination / Solution:
n
- 1.5 ; d' = nd
In
one side bubble depth is 5 cm
∴ Original depth = 1.5 x 5 = 7.5 cm
On
the other side depth is 3 cm
∴ Original depth = 1.5 x 3 = 4.5
cm
∴ Thickness is 7.5 + 4.5 = 12 cm
Q10. Light transmitted by Nicol prism is,
Answer : Option C
Explaination / Solution:
No Explaination.
