Electromagnetic Induction

If potential (in volts) in a region is expressed as V (x, y, z) = 6 xy-y +2 yz, the electric field (in N/C) at point (1,1,0) is 

A conducting circular loop is placed in a uniform magnetic field, B = 0.0025 T with its plane perpendicular to the loop. The radius of the loop is made to shrink at a constant rate of 1 mms^-1. The induced emf when the radius is 2 cm, is

• 2 πμ V

• πμ V

• πμ V/2

• πμ V/2

Which of the following statement is false or the properties of electromagnetic waves?

• Both electric and magnetic field vectors attain the maxima and minima at the same place and same time

• The energy in electromagnetic waves is divided equally between electric and magnetic  vectors

• Both electric and magnetic field vectors are parallel to each other and perpendicular to the direction of propagation of wave

• Both electric and magnetic field vectors are parallel to each other and perpendicular to the direction of propagation of wave

A condenser of capacity C is charged to a potential difference of V₁. The plates to the condenser are then connected to an ideal inductor of inductance L. The current through the inductor when the potential difference across the condenser reduces to V₂ is

The thermal emf E in volt of a certain thermocouple is found to vary with temperature difference θ in ^oC between the two junctions according to the relation

The neutral temperature for the thermocouple will be

• 450^o C

• 400^o C

• 225^o C

• 225^o C

A conducting circular loop is placed in uniform magnetic field 0.04 T with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at 2 mms^-1. The induced emf in the loop when the radius is 2 cm is 

• 3.2 π μ V

• 4.8 π μ V

• 0.8 π μ V

• 0.8 π μ V

The electric field part of an electromagnetic wave in a medium is represented by
E_x = 0;

• moving along y direction with frequency 2π x 10⁶ Hz and wavelength 200 m.

• moving along x direction with frequency 10⁶ Hz and wavelength 200 m.

• moving along x direction with frequency 10⁶ Hz and wavelength 200 m
  
  

• moving along x direction with frequency 10⁶ Hz and wavelength 200 m
  
  

See the electrical circuit shown in this figure. Which of the following equations is a correct equation for it?

Power dissipated in an L-C-R series circuit connected to an AC source of emf is

In the phenomenon of electric discharge through gases at low pressure, the coloured glow in  the tube appears as a result of 

• excitation of electrons in the atoms

• a collision between the atoms of the gas

• a collision between the charged particle emitted from the cathode and the atoms of the gas

• a collision between the charged particle emitted from the cathode and the atoms of the gas