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The ratio of the amplitude of the magnetic field to the amplitude of electric field for an electromagnetic wave propagating in vacuum is equal to:
A parallel plate capacitor is charged by connecting it to a battery through a resistor. If $i$ is the current in the circuit, then in the gap between the plates:
A rod of length $L$ rotates with a small uniform angular velocity $\omega$ about its perpendicular bisector. A uniform magnetic field $B$ exists parallel to the axis of rotation. The potential difference between the centre of the rod and an end is:
In an electromagnetic wave in free space the root mean square value of the electric field is $E_{rms} = 6$ V/m. The peak value of the magnetic field is:
The electric field of an electromagnetic wave in free space is given by $\vec{E} = 10 \cos(10^7 t + kx) \hat{j}$ V/m, where $t$ and $x$ are in seconds and meters respectively. It can be inferred that: (1) The wavelength $\lambda$ is $188.4 \text{ m}$. (2) The wave number $k$ is $0.33 \text{ rad/m}$. (3) The wave amplitude is $10 \text{ V/m}$. (4) The wave is propagating along $+x$ direction. Which one of the following pairs of statements is correct?
If the unit of length and force be increased four times, then the unit of energy is:
Which of the following pairs of physical quantities has the same dimensions?
A, B and C are three points in a uniform electric field. The electric potential is:
The electric potential at a point in free space due to a charge $Q$ coulomb is $Q \times 10^{11}$ V. The electric field at that point is:
Four point charges -Q, -q, 2q and 2Q are placed, one at each corner of the square. The relation between Q and q for which the potential at the centre of the square is zero, is
If potential in a region is expressed as $V(x,y,z) = 6xy - y + 2yz$, the electric field at point $(1, 1, 0)$ is:
Two spheres of radius $a$ and $b$ respectively are charged and joined by a wire. The ratio of the electric field at the surface of the spheres is:
The Earth Summit held in Rio de Janeiro in 1992 was called
Which one of the following ions is the most stable in aqueous solution? (At no. Ti=22, V=23, Cr=24, Mn=25)
Which of the following series of transitions in the spectrum of hydrogen atoms falls in the visible region?
The force $F$ on a sphere of radius ‘$a$’ moving in a medium with velocity ‘$v$’ is given by $F = 6\pi\eta av$. The dimensions of $\eta$ are:
Which of the following represents a volt?
Which one of the following electrons in the ground state will have the least amount of energy?
Two metal spheres, one of radius $R$ and the other of radius $2R$ respectively have the same surface charge density $\sigma$. They are brought in contact and separated. What will be the new surface charge densities on them?
A particle starting from the origin $(0,0)$ moves in a straight line in the $(x,y)$ plane. Its coordinates at a later time are $(\sqrt{3}, 3)$. The path of the particle makes an angle of __________ with the $x$-axis: