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One end of the string of length $l$ is connected to a particle of mass $m$ and the other end is connected to a small peg on a smooth horizontal table. If the particle moves in a circle with speed $v$, the net force on the particle (directed towards the centre) will be: ($T$ represents the tension in the string)
Newton's second law gives the measure of:
Consider aiming a beam of free electrons towards free protons. When they scatter, an electron and a proton cannot combine to produce a H-atom,
The colour code of resistance is given below: The values of resistance and tolerance, respectively are:
A series R-C circuit is connected to an alternating voltage source. Consider two situations: 1. When the capacitor is air-filled. 2. When the capacitor is mica filled. If the current through the resistor is $I$ and voltage across the capacitor is $V$, then:
The Balmer series for the H-atom can be observed: (a) if we measure the frequencies of light emitted when an excited atom falls to the ground state (b) if we measure the frequencies of light emitted due to transitions between excited states and the first excited state (c) in any transition in a H-atom (d) as a sequence of frequencies with the higher frequencies getting closely packed
In an AC circuit the emf (e) and the current (i) at any instant are given respectively by e = E₀ sin ωt, i = I₀ sin(ωt - ϕ). The average power in the circuit over one cycle of AC is
Power dissipated in an L-C-R series circuit connected to an AC source of emf ε is
An inductor 20 mH, a capacitor 50 μF, and a resistor 40 Ω are connected in series across a source of emf V = 10 sin 340t. The power loss in the AC circuit is:
An inductor of inductance 2 mH is connected to a 220 V, 50 Hz AC source. Let the inductive reactance in the circuit be $X_1$. If a 220 V DC source replaces the AC source in the circuit, then the inductive reactance in the circuit is $X_2$. $X_1$ and $X_2$, respectively, are:
The increase in the width of the depletion region in a p-n junction diode is due to:
Energy E of a hydrogen atom with principal quantum number n is given by E = -13.6/n² eV. The energy of a photon ejected when the electron jumps from n = 3 state to n = 2 state of hydrogen, is approximately:
The maximum power is dissipated for an AC in a/an:
Three blocks A, B, and C of masses $4 \text{ kg}$, $2 \text{ kg}$, and $1 \text{ kg}$ respectively, are in contact on a frictionless surface, as shown. If a force of $14 \text{ N}$ is applied to the $4 \text{ kg}$ block, then the contact force between A and B is:
As the frequency of an AC circuit increases, the current first increases and then decreases. Which of the following combinations of circuit elements is most likely to comprise the circuit? (a) Inductor and capacitor (b) Resistor and inductor (c) Resistor and capacitor (d) Resistor, inductor, and capacitor
Three blocks A, B and C of masses $4 \text{ kg}$, $2 \text{ kg}$ and $1 \text{ kg}$ respectively, are in contact on a frictionless surface, as shown. If a force of $14 \text{ N}$ is applied on the $4 \text{ kg}$ block, then the contact force between A and B is:
The core of a transformer is laminated so that:
Two carts of masses 200 kg and 300 kg on horizontal rails are pushed apart. Suppose the coefficient of friction between the carts and the rails are the same. If the 200 kg cart travels a distance of 36 m and stops, then the distance travelled by the cart weighing 300 kg is:
A block of mass $m$ is in contact with the cart C as shown in the figure. The coefficient of static friction between the block and the cart is $\mu$. The acceleration $\alpha$ of the cart that will prevent the block from falling satisfies:
A body, under the action of a force $\vec{F} = 6\hat{i} - 8\hat{j} + 10\hat{k}$, acquires an acceleration of $1 \text{ ms}^{-2}$. The mass of this body must be: