1. Visible light has wavelengths in the range of \(400 \,\text{nm}\) to \(780 \,\text{nm}\). Calculate the range of energy of the photons of visible light. Solution:  The energy (\(E\)) of a photon is calculated using the formula: $$E = \frac{hc}{\lambda}$$ Given constants: Planck constant (\(h\)): \(6.63 \times 10^{-34} \,\text{J s}\) Speed of light (\(c\)): \(3 …

Photoelectric Effect & Wave Particle Duality | H C Verma | Solution Read More »

1. Can the centre of mass of a body be at a point outside the body? Answer: Yes Explanation: The centre of mass (COM) is the point where the entire mass of a body can be considered to be concentrated for the purpose of analyzing motion. It depends on the distribution of mass and not …

Concept of Physics | H VC Verma | Solution | Centre of Mass | Linear Momentum | Collision Read More »

1. The dimension of \(\dfrac{B^2}{2\mu_0}\), where \(B\) is the magnetic field and \(\mu_0\) is the magnetic permeability of vacuum, is: 1. \([ML^{-1}T^{-2}]\) 2. \([ML^2T^{-1}]\) 3. \([MLT^{-2}]\) 4. \([ML^2T^{-2}]\) Solution: The quantity \(\dfrac{B^2}{2\mu_0}\) represents magnetic energy stored per unit volume (Energy Density). Energy Density \(=\dfrac{\text{Energy}}{\text{Volume}}\) \[ \left[\frac{B^2}{\mu_0}\right] = \frac{ML^2T^{-2}}{L^3} = \boxed{ML^{-1}T^{-2}} \] Answer: 1. \([ML^{-1}T^{-2}]\) 2. …

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1. Young’s modulus of elasticity \( Y \) is expressed in terms of three derived quantities, namely, the gravitational constant \( G \), Planck’s constant \( h \) and the speed of light \( c \), as \( Y = c^\alpha h^\beta G^\gamma \). Which of the following is the correct option? [JEE (Advanced) 2023] …

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QUESTIONS FOR SHORT ANSWER 1. When you lift a box from the floor and put it on an almirah the potential energy of the box increases, but there is no change in its kinetic energy. Is it a violation of conservation of energy? Solution:  No, this is not a violation of the conservation of energy. …

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1. You are driving a motorcycle on a horizontal road. It is moving with a uniform velocity. Is it possible to accelerate the motorcycle without putting higher petrol input rate into the engine? Solution: Yes, it is possible to accelerate the motorcycle without increasing the petrol input rate. Velocity is a vector quantity, having both …

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QUESTIONS FOR SHORT ANSWER 1 A For most of the surfaces used in daily life, the friction coefficient is less than 1. Is it always necessary that the friction coefficient is less than 1? Answer: No Explanation: It is not always necessary for the friction coefficient to be less than 1. While many common surfaces …

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QUESTIONS FOR SHORT ANSWER 1. The apparent weight of an object increases in an elevator while accelerating upward. A moongphaliwala sells his moongphali using a beam balance in an elevator. Will he gain more if the elevator is accelerating up ? Answer: No Explanation: The beam balance works on the principle of comparison of masses. …

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QUESTIONS FOR SHORT ANSWER 1. A body of mass \( m \) is placed on a table. The earth is pulling the body with a force \( mg \). Taking this force to be the action what is the reaction ? Answer: The reaction is the gravitational force with which the body pulls the earth. …

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