If c is the velocity of light in free space, the time taken by light to travel
If c is the velocity of light in free space, the time taken by light to travel a distance x in a medium refractive index μ is
Options
(a) x/c (b) μx/c (c) […]
MP2013
A current of 2 A is made to flow through a coil which has only one turn. The magnetic
A current of 2 A is made to flow through a coil which has only one turn. The magnetic field produced at the centre is 4πx10⁻⁶ Wb/m². The radius of the coil is
Options […]
On heating a ferromagnetic substance above curie temperature
On heating a ferromagnetic substance above curie temperature
Options
(a) becomes paramagnetic (b) becomes diamagnetic (c) remains ferromagnetic with constant magnetic susceptibility (d) becomes electromagnetic
Correct Answer:
becomes paramagnetic
Explanation:
No explanation available. […]
For having large magnification power of a compound microscope
For having large magnification power of a compound microscope
Options
(a) length of the microscope tube must be small (b) focal lengths of objective lens and eye-piece should be large. (c) focal lengths […]
The radius of curvature of the convex face of a plano-convex lens is 12 cm
The radius of curvature of the convex face of a plano-convex lens is 12 cm and the refractive index of the material of the lens is 1.5. Then, the focal length of the lens is […]
Two thin lenses of focal lengths f₁ and f₂ are in contact and coaxial.
Two thin lenses of focal lengths f₁ and f₂ are in contact and coaxial. The power of the combination is:
Options
(a) √ f₁ / f₂ (b) √ f₂ / f₁ (c) f₁ […]
Electrical force is acting between two charges kept in vacuum. A copper plate
Electrical force is acting between two charges kept in vacuum. A copper plate is placed between the charges, the force now is
Options
(a) more (b) less but not zero (c) remains unchanged […]
A point charge q is placed at a distance x/2 directly above the centre of a cube
A point charge q is placed at a distance x/2 directly above the centre of a cube of side x. The flux through the cube is
Options
(a) q/ε₀ (b) q/2ε₀ (c) q/4ε₀ […]
When a p-n junction is reverse biased, then the current through the junction
When a p-n junction is reverse biased, then the current through the junction is mainly due to
Options
(a) Only diffusion of charges (b) Only drift of charges (c) Both drift and diffusion of […]
Maximum kinetic energy of electrons emitted in photoelectric effect increases when
Maximum kinetic energy of electrons emitted in photoelectric effect increases when
Options
(a) intensity of light is increased (b) light source is brought nearer the metal (c) frequency of light is decreased (d) […]