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8 months ago

Class 12th Dual Nature of Radiation and Matter

The equation $λ = \frac{1.227}{x} n m$ can be used to find the de-Brogli wavelength of an electron. In this equation x stands for:

Where m = mass of electron

P = momentum of electron

K = kinetic energy of electron

V = Accelerating potential in volts for electron

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Vishal Baghel

Contributor-Level 10

Kindly consider the following answer

x = $\sqrt[]{V}$

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8 months ago

Class 12th Physics

In normal adjustment, for a refracting telescope, the distance between objective and eye piece is 30cm. The focal length of the objective, when the angular magnification of the telescope is 2, will be:

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Vishal Baghel

Contributor-Level 10

Angular magnification, $θ = | \frac{f_{0}}{f_{e}} |$ $\frac{_{}}{_{}}$

Length of tuber L = $| f_{0} | + | f_{e} |$ $_{}_{}$

$| f_{0} | + | f_{e} | = 30 c m$

$A s, | \frac{f_{0}}{f_{e}} | = 2$

$| f_{0} | = 2 | f_{e} |$

$\Rightarrow | f_{0} | + \frac{| f_{0} |}{2} = 30 \Rightarrow | f_{0} | = \frac{2}{3} * 30 = 20 c m$

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8 months ago

Class 12th Physics Wave Optics

An unpolarised light beam of intensity 2l₀ is passed through a polaroid P and then through another polaroid Q which is oriented is such a way that its passing axis makes an angle of 30° relative to that of P. The intensity of the emergent light is

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alok kumar singh

Contributor-Level 10

$I = I_{0} c o s^{2} 30 °$

$= I_{0} {(\frac{\sqrt[]{3}}{2})}^{2} = \frac{3}{4} I_{0}$

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8 months ago

Class 12th Physics

As shown in the figure, after passing through the medium 1. The speed of light $υ_{2}$ in medium 2 will be:

(Given c = 3 * 10⁸ ms^-¹)

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Vishal Baghel

Contributor-Level 10

In a medium, speed of light, $V = \frac{C}{\sqrt[]{μ_{r} ε_{r}}} = \frac{3 * 1 0^{8} m / s}{\sqrt[]{1 * 9}} = 1 * 1 0^{8} m / s$

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Class 12th Physics

A circuit element X when connected to an a.c. supply of peak voltage 100V given a peak current of 5A which is in phase with the voltage. A second element Y when connected to the same a.c. supply also gives the same value of peak current which lags behind the voltage by If X and Y are connected in series to the same supply, what will be the rms value of the current in ampere?

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alok kumar singh

Contributor-Level 10

v = 100 sin $ω t$

$i_{0} = \frac{100}{R_{x}} = 5 \Rightarrow R_{x} = 20 Ω$

i = $5 s i n (ω t - \frac{π}{2})$

i = 100 5sin $ω t$ &nb

...more

v = 100 sin $ω t$

$i_{0} = \frac{100}{R_{x}} = 5 \Rightarrow R_{x} = 20 Ω$

i = $5 s i n (ω t - \frac{π}{2})$

i = 100 5sin $ω t$

$5 = \frac{100}{R_{y}} \Rightarrow R_{y} = \frac{100}{5} = 20 Ω$

When x and y both are connected in series :-

v = 100sin $ω t$

tanθ = 1 = q = 45°

R₀ = $\sqrt[]{R_{x}^{2} + R_{y}^{2}} = 20 \sqrt[]{2} Ω$

$∴ \overset{o}{l_{0}} = \frac{v_{0}}{R_{0}} = \frac{100}{20 \sqrt[]{2}} = \frac{5}{\sqrt[]{2}} A .$

$∴ l_{m s} = \frac{l_{0}}{\sqrt[]{2}}$

$= \frac{5}{\sqrt[]{2} \cdot \sqrt[]{2}}$

$= \frac{5}{2} A = \frac{5}{2} A$

less

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8 months ago

Class 12th Physics

The equation of current in a purely inductive circuit is 5sin(49pt – 30°). If the inductance is 30 mH then the equation for the voltage across the inductor, will be: ${L e t π = \frac{22}{7}}$

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Vishal Baghel

Contributor-Level 10

$i = 5 s i n (49 π t - 30 °)$

$L = 30 m H, π = \frac{22}{7}$

$X_{L} = ω L = 49 π * 30 * 1 0^{- 3}$

$= 49 \frac{22}{7} * 30 * 1 0^{- 3}$

$V_{L} = 23.1 s i n (49 π t + 60 °)$

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Class 12th Physics Moving Charges and Magnetism

As shown in the figure, a metallic rod of linear density 0.45 km^-¹ is lying horizontally on a smooth incline plane which makes an angle of 45° 5with the horizontal. The minimum current flowing in the rod required to keep it stationary, when 0.15 T magnetic field is acting on it in the vertical upward direction, will be:

{Use g = m/s²}

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Vishal Baghel

Contributor-Level 10

Linear density, $λ =$ 0.45 kg/m

Let length = $l$ $∴$ = m = 0.45 $l$

B = 0.15 T

For equilibrium of rod :-

mg sin 45° = FB sin 45°

$\Rightarrow (0.45 l) g = l l B$

So, $l = \frac{0.45 * 10}{0.15} = 30 A$ $\frac{}{}$

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8 months ago

Class 12th Physics Moving Charges and Magnetism

The current sensitivity of a galvanometer can be increased by:

(a) decreasing the number of turns

(b) increasing the magnetic field

(c) decreasing the area of the coil

(d) decreasing the torsional constant of the spring

Choose the most appropriate answer from the options given below:

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Vishal Baghel

Contributor-Level 10

Current sensitivity, $\frac{}{}$ $S i = \frac{N A B}{k}$

$N i A B = k θ$

$θ = (\frac{N A B}{k}) i$

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8 months ago

Class 12th Physics

A wire of resistance R₁ is drawn out so that its length is increased by twice of its original length. The ratio of new resistance to original resistance is:

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Vishal Baghel

Contributor-Level 10

$R_{2} = ρ \frac{2 l}{A / 2} = \frac{4 ρ l}{A} = 4 R_{1}$
$\frac{R_{2}}{R_{1}} = \frac{4}{1} \to 4 : 1$

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8 months ago

Class 12th Physics Moving Charges and Magnetism

A wire X of length 50cm carrying a current of 2A is placed parallel to a long wire Y of length 5m. The wire Y current of 3A. The distance between two wires is 5cm and currents flow in the same direction. The force acting on the wire Y is

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alok kumar singh

Contributor-Level 10

F_x_-y = $\frac{μ_{0} i_{1} i_{2}}{2 π r} * (. 5)$

$= \frac{2 * 1 0^{- 7} * 6 * 0.5}{0.05}$

$= \frac{6}{5} * 1 0^{- 5} N = 1.2 * 1 0^{- 5}$

Force on Y = 1.2 * 10^-5N towards 'x'

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