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The net magnetic flux through any closed surface is:
Magnetic monopoles do not exist; field lines form closed loops, so net flux through any closed surface is zero.
If the galvanometer $G$ does not show any deflection in the circuit shown, the value of $R$ is given by:
No deflection in $G$ means no current through it, so voltage across $R$ equals the 2 V cell EMF. Current in the outer loop = $(10-2)/400 = 0.02\ \text{A}$, hence $R = 2/0.02 = 100\ \Omega$.
In a series $LCR$ circuit, the inductance $L$ is $10\ \text{mH}$, capacitance $C$ is $1\ \mu\text{F}$ and resistance $R$ is $100\ \Omega$. The frequency at which resonance occurs is:
$f_0 = \dfrac{1}{2\pi\sqrt{LC}} = \dfrac{1}{2\pi\sqrt{10^{-2}\times 10^{-6}}} \approx 1.59\ \text{kHz}$.
The temperature of a gas is $-50^\circ\text{C}$. To what temperature the gas should be heated so that the rms speed is increased by 3 times?
$v_{rms}\propto\sqrt{T}$. "Increased by 3 times" $\Rightarrow v\to 4v$, so $T\to 16T$. $T_1 = 223\ \text{K}$, $T_2 = 16 \times 223 = 3568\ \text{K} = 3295^\circ\text{C}$.
Let a wire be suspended from the ceiling (rigid support) and stretched by a weight $W$ attached at its free end. The longitudinal stress at any point of cross-sectional area $A$ of the wire is:
Tension throughout the wire equals $W$; stress = tension/area = $W/A$.
A Carnot engine has an efficiency of 50% when its source is at a temperature $327^\circ\text{C}$. The temperature of the sink is:
$\eta = 1 - T_2/T_1\Rightarrow 0.5 = 1 - T_2/600\Rightarrow T_2 = 300\ \text{K} = 27^\circ\text{C}$.
Resistance of a carbon resistor determined from colour codes is $(22000 \pm 5\%)\ \Omega$. The colour of third band must be:
$22000 = 22 \times 10^3$. First two bands red, red (2,2); third band (multiplier $10^3$) is orange.
The minimum wavelength of $X$-rays produced by an electron accelerated through a potential difference of $V$ volts is proportional to:
$\lambda_{\min} = \dfrac{hc}{eV}\Rightarrow \lambda_{\min}\propto \dfrac{1}{V}$.
For Young's double slit experiment, two statements are given below:
Statement I: If screen is moved away from the plane of slits, angular separation of the fringes remains constant.
Statement II: If the monochromatic source is replaced by another monochromatic source of larger wavelength, the angular separation of fringes decreases.
In the light of the above statements, choose the correct answer from the options given below:
Angular separation $\theta = \lambda/d$ is independent of screen distance (Statement I true). For larger $\lambda$, $\theta$ increases, not decreases (Statement II false).
The work functions of Caesium (Cs), Potassium (K) and Sodium (Na) are $2.14\ \text{eV}$, $2.30\ \text{eV}$ and $2.75\ \text{eV}$ respectively. If incident electromagnetic radiation has an incident energy of $2.20\ \text{eV}$, which of these photosensitive surfaces may emit photoelectrons?
Photoemission requires photon energy $\ge$ work function. Only $W_{Cs} = 2.14 < 2.20$ eV.
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The bank mixes NEET previous year questions (PYQs) with practice questions, each tagged with its exam appearances where applicable.