Question
A plane wave front falls on a convex lens. The emergent wave front is:
✓
Answer
- Spherical converging
A convex lens is thicker at the middle. When a light ray is incident parallel
to principle axis it is refracted towards the focal point. Similarly when a plane wave front is incident on a convex lens the light is refracted towards a point on the focal plane.
As the light is getting focused at a point it is converging and the emerging wave front is a spherical converging.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The value of magnetic potential at a distance $r$ from a pole strength $m$ is :
→The electric potential is measured in:
Assertion : Lenz’s law violates the principle of conservation of energy.
Reason : Induced e.m.f., opposes always the change in magnetic flux responsible for its production.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If assertion is false but reason is true.
Reason : Induced e.m.f., opposes always the change in magnetic flux responsible for its production.(a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If assertion is false but reason is true.
The length of a wire of a potentiometer is $100 \ cm ,$ and the emf of its standard cell is $E$ volt. It is employed to measure the $e.m.f$ of a battery whose internal resistance is $0.5 \Omega$. If the balance point is obtained at $I = 30 \ cm$ from the positive end, the $e.m.f.$ of the battery is $($where is the current in the potentiometer$)$
→In the circuit shown in the figure, the current flowing in $2 \Omega$ resistance
→I a.m.u. is equivalent to the energy of :
The resistance of a galvanometer coil is $R$. What is the shunt resistance required to convert it into an ammeter of range $4$ times
→When a dielectric is introduced between the plates of a condenser, the capacity of condenser:
How many resistances are used in a Wheatstone bridge?
When light enters from air to water, then its(a) Frequency increases and speed decreases(b) Frequency is same but the wavelength is smaller in water than in air(c) Frequency is same but the wavelength in water is greater than in air(d) Frequency decreases and wavelength is smaller in water than in air