In isothermal process, which of the following is not true?
Temperature remains constant
Internal energy does not change
No heat enters or leaves the system
none of the above
Two equal -ve charges -q are fixed at the point (O, a) and (O, a) on the y-axis. A positive charge Q is released from rest at the point (2a, 0) on the x-axis. The charge will :
execute SHM about the origin
move to the origin and remain at rest
move to infinity
execute oscillatory but not SHM
A charge Q is distributed uniformly in a sphere (solid). Then, the electric field at any point r, where, r < R (r is the radius of sphere) varies as:
r -1
r
r -2
In the given circuit, what will be the equivalent resistance between the points A and B ?
10 / 3 Ω
20 / 3 Ω
10 / 5 Ω
5 Ω
If a charge particle enters perpendicularly in the uniform magnetic field, then:
energy and momentum both remains constant
energy remains constant but momentum changes
both energy and momentum changes
energy changes but momentum remains constant
A uniform wire of length I and having resistance R is cut into n equal parts and all parts are connected in parallel, then the equivalent resistance will be :
R
R/n
R/n2
n2R
In a L-C-R circuit, the capacitance is made one-fourth, then what should be changed in inductance, so that the circuit remains in resonance?
8 IMES
1/4 times
2 times
4 times
The light rays having photons of energy 1.8 eV are falling on a metal surface having a work function 1.2 eV. What is the stopping potential to be applied to stop the emitting electrons?
3 eV
1.2 eV
0.6 eV
1.4 eV
C.
0.6 eV
The stopping potential depends on the kinetic energy of the electrons, which is affected only by the frequency of incoming light and not by its intensity.
The maximum kinetic energy of the photoelectron
(KE)max = E - Φ =1.8-1.2
= 0.6 eV
i.e eVo = (KE)max
or eVo = 0.6 eV
∴ Stopping potential Vo = 0.6 V
1f the focal length of a lens of a camera is 5f and that of another is 2.5f, what is the time of exposure for the second, if for the first one is ? (where f is focal length / unit aperture)