Given below are two statements : one is labelled as AssertionA and the other is labelled as ReasonR.
Assertion A : The photoelectric effect does not takes place, if the energy of the incident radiation is less than the work function of a metal.
Reason R :Kinetic energy of the photoelectrons is zero, if the energy of the incident radiation is equal to the work function of a metal.
In the light of the above statements, choose the most appropriate answer from the options given below.
Given below are two statements : one is labelled as AssertionA and the other is labelled as ReasonR.
Assertion A : The photoelectric effect does not takes place, if the energy of the incident radiation is less than the work function of a metal.
Reason R :Kinetic energy of the photoelectrons is zero, if the energy of the incident radiation is equal to the work function of a metal.
In the light of the above statements, choose the most appropriate answer from the options given below.
- Both A and R are correct and R is the correct explanation of A
- Both A and R are correct but R is not the correct explanation of A
- A is correct but R is not correct
- A is not correct but R is correct
The Correct Option is B
Solution and Explanation
The correct option is(B): Both A and R are correct but R is not the correct explanation of A
When energy of incident radiation is equal to the work function of the metal, then the KE of photoelectrons would be zero. But this statement does not comment on the situation when energy is less than the work function.
Top Questions on Gravitational Potential Energy
- A ball is thrown vertically upwards with a speed of \( 20 \, \text{m/s} \). What is the maximum height reached by the ball? Assume the acceleration due to gravity is \( g = 9.8 \, \text{m/s}^2 \).
- VITEEE - 2025
- Physics
- Gravitational Potential Energy
- A particle of mass \( m \) is at a distance \( 3R \) from the center of Earth. Find the minimum kinetic energy of the particle to leave Earth's field, where \( R \) is the radius of Earth.
- JEE Main - 2025
- Physics
- Gravitational Potential Energy
- What is the expression for the time period of a satellite orbiting Earth at a height \( h \) above the Earth's surface?
- MHT CET - 2024
- Physics
- Gravitational Potential Energy
- A satellite moving around the Earth in a circular orbit has kinetic energy \( E \). Then, the minimum amount of energy to be added so that it escapes from the Earth is:
- AP EAMCET - 2024
- Physics
- Gravitational Potential Energy
- The gravitational potential energy of a body on the surface of the Earth is \(E\). If the body is taken from the surface of the Earth to a height equal to \(150%\) of the radius of the Earth, its gravitational potential energy is:
- AP EAMCET - 2024
- Physics
- Gravitational Potential Energy
Questions Asked in JEE Main exam
If $10 \sin^4 \theta + 15 \cos^4 \theta = 6$, then the value of $\frac{27 \csc^6 \theta + 8 \sec^6 \theta}{16 \sec^8 \theta}$ is:
- JEE Main - 2025
- Trigonometric Identities
If the area of the region $\{ (x, y) : |x - 5| \leq y \leq 4\sqrt{x} \}$ is $A$, then $3A$ is equal to
- JEE Main - 2025
- Area between Two Curves
Let $A = \begin{bmatrix} \cos \theta & 0 & -\sin \theta \\ 0 & 1 & 0 \\ \sin \theta & 0 & \cos \theta \end{bmatrix}$. If for some $\theta \in (0, \pi)$, $A^2 = A^T$, then the sum of the diagonal elements of the matrix $(A + I)^3 + (A - I)^3 - 6A$ is equal to
- JEE Main - 2025
- Matrices
Let $A = \{ z \in \mathbb{C} : |z - 2 - i| = 3 \}$, $B = \{ z \in \mathbb{C} : \text{Re}(z - iz) = 2 \}$, and $S = A \cap B$. Then $\sum_{z \in S} |z|^2$ is equal to
- JEE Main - 2025
- Determinants
Let $C$ be the circle $x^2 + (y - 1)^2 = 2$, $E_1$ and $E_2$ be two ellipses whose centres lie at the origin and major axes lie on the $x$-axis and $y$-axis respectively. Let the straight line $x + y = 3$ touch the curves $C$, $E_1$, and $E_2$ at $P(x_1, y_1)$, $Q(x_2, y_2)$, and $R(x_3, y_3)$ respectively. Given that $P$ is the mid-point of the line segment $QR$ and $PQ = \frac{2\sqrt{2}}{3}$, the value of $9(x_1 y_1 + x_2 y_2 + x_3 y_3)$ is equal to
- JEE Main - 2025
- Coordinate Geometry
Concepts Used:
Work, Energy and Power
Work:
- Work is correlated to force and the displacement over which it acts. When an object is replaced parallel to the force's line of action, it is thought to be doing work. It is a force-driven action that includes movement in the force's direction.
- The work done by the force is described to be the product of the elements of the force in the direction of the displacement and the magnitude of this displacement.
Energy:
- A body's energy is its potential to do tasks. Anything that has the capability to work is said to have energy. The unit of energy is the same as the unit of work, i.e., the Joule.
- There are two types of mechanical energy such as; Kinetic and potential energy.
Read More: Work and Energy
Power:
- Power is the rate at which energy is transferred, conveyed, or converted or the rate of doing work. Technologically, it is the amount of work done per unit of time. The SI unit of power is Watt (W) which is joules per second (J/s). Sometimes the power of motor vehicles and other machines is demonstrated in terms of Horsepower (hp), which is roughly equal to 745.7 watts.
- Power is a scalar quantity, which gives us a quantity or amount of energy consumed per unit of time but with no manifestation of direction.