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The electric field of EM wave is 6 volt/m. The magnetic field associated with the wave if the wave is propagating in the +x direction and electric field along y-axis is:

a. b. c. d. Answer: (b) E = BC... View Article

A capacitor of capacitance C = 15 pF is charged with voltage V = 500 V. The electric field inside the capacitor with dielectric is 10⁶ V/m and the area of the plate is 10^{– 4} m², then the dielectric constant of the medium is: ( [latex]{{varepsilon }_{0}}=8.85times {{10}^{-12}}[/latex] in SI units)

a.12.47 b.8.47 c.10.85 d.14.85 Answer: (b) C = 15PF V = 500V E = 106 V/m A = 10– 4 m2 E = V/d = 8.47... View Article

ASEEM Portal [UPSC Notes]

ASEEM or Aatamanirbhar Skilled Employee Employer Mapping is a Skill Management Information System that acts as a directory of the skilled... View Article

Draft Drone Rules 2021: RSTV – Big Picture

Rajya Sabha TV programs and discussions are very insightful and informative from a UPSC perspective. In this article, we provide a gist of the... View Article

Parts of the Indian Constitution [UPSC Polity Notes]

The Constitution of India, its Parts, Schedules, and Articles are very important topics for the UPSC exam. It is a crucial part of the polity... View Article

22 July 2021: UPSC Exam Comprehensive News Analysis

CNA 22nd July 2021:- Download PDF Here TABLE OF CONTENTS A. GS 1 Related B. GS 2 Related POLITY AND GOVERNANCE 1. HC stays Arunachal’s entry... View Article

The resistance of the meter bridge AB in the given figure is [latex]4Omega[/latex]. With a cell of emf = 0.5 V and rheostat resistance Rh = [latex]2Omega[/latex] the null point is obtained at some point J. When the cell is replaced by another one of emf [latex]varepsilon =varepsilon _{2}[/latex] the same null point J is found for [latex]R_{h}=6Omega[/latex]. The emf [latex]varepsilon _{2}[/latex] is;

a. 0.3 V b. 0.5 V c. 0.4 V d. 0.6 V Answer: (a) Rh = ---------(1) When Rh = ----(2) From (1) and (2)... View Article

The variation of refractive index of a crown glass thin prism with wavelength of the incident light is shown. Which of the following graphs is the correct one, if Dm is the angle of minimum deviation?

Answer: (a) Since Dm = (μ – 1)A and on increasing the wavelength, μ decreases and hence Dm decreases. Therefore, correct answer is (a)... View Article

an amplitude modulated signal is given by vt

a. 1785 and 1715 b. 892.5 and 857.5 c. 89.25 and 85.75 d. 178.5 and 171.5 Answer: (c) , , , , , , Closest answer is (c)... View Article

In the given circuit the current through Zener Diode is close to:

a. 6.7 mA b. 4.0 mA c. 0.0 mA d. 6.0 mA Answer: (c) Since voltage across zener diode must be less than 10V therefore it will not work... View Article

A hydrogen atom, initially in the ground state is excited by absorbing a photon of wavelength 980Å. The radius of the atom in the excited state, in terms of Bohr radius a0, will be: (hc = 12500 eV – Å)

a. 9a0 b. 25a0 c. 4a0 d. 16a0 Answer: (d) Energy of photon =12500/980 = 12.75eV Electron will excite to n= 4 Since, R ∝ n2 Radius of... View Article

If the deBroglie wavelength of an electron is equal to 10³ times the wavelength of a photon of frequency 6×10 ¹⁴Hz, then the speed of electron is equal to : (Speed of light = 3×10 ⁸m/s, Planck’s constant = 6.63×10³⁴J . Mass of electron = 9.110³¹kg)

a. 1.8 x 106 m/s b. 1.45 x 106 m/s c. 1.1 x 106 m/s d. 1.7 x 106 m/s Answer: (b) V = 1.45 x 106 m/s... View Article

In a Young’s double slit experiment, the path difference, at a certain point on the screen between two interfering waves is (1/8)^th of wavelength. The ratio of the intensity at this point to that at the centre of a bright fringe is close to

a. 0.74 b. 0.80 c. 0.85 d. 0.94 Answer: (c)... View Article

An object at a distance of 20m from a convex lens of focal length 0.3m. The lens forms an image of the object. If the object moves away from the lens at a speed of 5m/s, the speed and direction of the image will be

a. 3.22 × 10–3 m/s towards the lens b. 2.26 × 10–3 m/s away from the lens c. 1.16 × 10–3 m/s towards the lens d. 0.92 × 10–3 m/s away from the... View Article

An electromagnetic wave of intensity 50 Wm^-2 enters in a medium of refractive index ‘n’ without any loss. The ratio of the magnitudes of electric fields, and the ratio of the magnitudes of magnetic fields of the wave before and after entering into the medium are respectively, given by

a. b. c. d. Answer: (b) (For transparent medium ) Therefore, Similarly,... View Article

In the below given circuit the switch S₁ is closed at time t = 0 and the switch S₂ is kept open. At some later time (t₀), the switch S₁ is opened and S₂ is closed. The behavior of the current I as a function of time ‘t’ is given by:

Answer: (2) From time t = 0 to t = t0, growth of current takes place and after that decay of current takes place.... View Article

There are two long co-axial solenoids of same length l. the inner and outer coils have radii r₁ and r₂ and number of turns per unit length n₁ and n₂ respectively. The ratio of mutual inductance to the self-inductance of the inner-coil is:

a. b. c. d. Answer: (d) Mutual Inductance= Self Inductance = Ratio = n2/n1... View Article

In an experiment, electrons are accelerated, from rest, by applying a voltage of 500 V.

Calculate the radius of the path if a magnetic field 100 mT is then applied. [Charge of the electron = 1.6 × 10-19 C Mass of the electron = 9.1... View Article

In a Wheatstone bridge (see fig.), resistances P and Q are approximately equal. When R = 400 Ω, the bridge is equal. When R = 400 Ω, the bridge is balanced. On inter-changing P and Q, the value of R, for balance, is 405 Ω. The value of X is close to

a. 403.5 ohm b. 404.5 ohm c. 401.5 ohm d. 402.5 ohm Answer: (d) Initially -----------(1) After interchanging P and Q -----------(2)... View Article

Two equal resistance when connected in series to a batter, consume electric power of 60 W. If these resistances are now connected in parallel combination to the same battery, the electric power consumed will be:

a. 60 W b. 240 W c. 30 W d. 120 W Answer: (b) In series condition, equivalent resistance is 2R thus power consumed is 60W P =60 =... View Article