Extraction of silver is achieved by initial complexation of the ore (Argentite) with X followed by reduction
with Y. X and Y respectively are
(A) CN– and Zn (B) CN– and Cu (C) Cl– and Zn (D) Br– and Zn
The Quantum Hall Resistance RH is a fundamental constant with dimensions of resistance. If h is Planck's
constant and e the electron charge, then the dimension of RH is the same as -
(A) e^2/h (B) h/e^2 (C) h^2/e (D) e/h^2
The total radiative power emitted by spherical blackbody with radius R and temperature T is P. If the radius
if doubled and the temperature is halved then the radiative power will be -
(A) P/4 (B) P/2 (C) 2P (D) 4P
Due to transitions among its first three energy levels, hydrogenic atom emits radiation at three discrete
wavelengths λ1, λ2, and λ3 (λ1 < λ2 < λ3). Then -
(A) λ1 = λ2 + λ3 (B) λ1 + λ2 = λ3 (C) 1/λ1 + 1/λ2 = 1/λ3 (D) 1/λ1 = 1/λ2 + 1/λ3
An electron collides with a free molecules initially in its ground state. The collision leaves the molecules in
an excited state that is metastable and does not decay to the ground state by radiation. Let K be the sum of
the initial kinetic energies of the electron and the molecule, and P
r
the sum of their initial momenta. Let K'
and P' represent the same physical quantities after the collision. Then -
(A) K = K', P = P' (B) K' < K, P = P' (C) K = K', P ≠ P' (D) K' < K, P ≠ P'
In a Young's double slit set-up, light from a laser source falls on a pair of very narrow slits separated by 1.0
micrometer and bright fringes separated by 1.0 millimeter are observed on a distant screen. If the frequency
of the laser light is doubled, what will be the separation of the bright fringes ?
(A) 0.25 mm (B) 0.5 mm (C) 1.0 mm (D) 2.0 mm
At 23ºC, a pipe open at both ends resonates at a frequency of 450 hertz. At what frequency does the same
pipe resonate on a hot day when the speed of sound is 4 percent higher than it would be at 23ºC ?
(A) 446 Hz (B) 454 Hz (C) 468 Hz (D) 459 Hz
A plane polarized light passed through successive polarizers which are rotated by 30º with respect to each
other in the clockwise direction. Neglecting absorption by the polarizers and given that the first polarizer's
axis is parallel to the plane of polarization of the incident light, the intensity of light at the exit of the fifth
polarizer is closest to -
(A) same as that of the incident light (B) 17.5% of the incident light
(C) 30% of the incident light (D) zero
A speaker emits a sound wave of frequency f0. When it moves towards a stationary observer with speed u,
the observer measures a frequency f1. If the speaker is stationary, and the observer moves towards it with
speed u, the measured frequency is f2. Then -
(A) f1 = f2 < f0 (B) f1 > f2 (C) f1 < f2 (D) f1 = f2 > f0