Email
Chat with tutors
logo

Ask Questions, Get Answers

X
 

Answers posted by priyanka.clay6

2010
answers
0
best answers
0 votes
If the kinetic energy of the particle is increased to 16 times its previous value, the percentage change in the de-Broglie wavelength of the particle is:
answered Feb 11, 2020
De Broglie wavelength $\lambda = \frac{h}{mv}$$\qquad \lambda = \frac{h}{\sqrt{2 m K}}$$\qquad \larg...
0 votes
When a metallic surface is illuminated with radiation of wavelength $\lambda$, the stopping potential is $V$. If the same surface is illuminated with radiation of wavelength $2 \lambda$, the stopping potential is $\frac{V}{4}$. The threshold wavelength for the metallic surface is :
answered Feb 11, 2020
Stopping potential $= V$;$W - $ work function$\therefore eV = \large\frac{hc}{\lambda}-w ---(1)$$\;\...
0 votes
A potentiometer wire is 100 cm long and a constant potential difference is maintained across it. Two cells are connected in series first to support one another and then in opposite direction. The balance points are obtained at 50 cm and 10 cm from the positive end of the wire in the two cases. The ratio of emf’s is :
answered Feb 11, 2020
Balance point is 50 cm when in series.$\qquad E_1+E_2=x(50)---(1)$Balance point is $10\;cm$ when in ...
0 votes
To get output 1 for the following circuit, the correct choice for the input is :
answered Feb 11, 2020
To get output 1$A = 1 \qquad B = 0 \qquad C = 1$
0 votes
A capacitor of $2 \mu F$ is charged as shown in the diagram. When the switch $S$ is turned to position $2$, the percentage of its stored energy dissipated is :
answered Feb 11, 2020
Total energy stored in the two capacitor together$\Delta U= \frac{1}{2} C_{eff} \;V^2$$\qquad = \lar...
0 votes
A beam of light consisting of red, green and blue colors is incident on a right angled prism. The refractive index of the material of the prism for the above red, green and blue wavelengths are 1.39, 1.44 and 1.47, respectively.

The prism will :
answered Feb 10, 2020
https://clay6.com/mpaimg/1779_a.jpg Since no emergence takes place. Incident angle must be ...
0 votes
A photoelectric surface is illuminated successively by monochromatic light of wavelength $\lambda$ and $\frac{\lambda}{2}$ . If the maximum kinetic energy of the emitted photoelectrons in the seconds case is 3 times that in the first case, the work function of the surface of the material is :
(h = Planck’s constant, c = speed of light)
answered Feb 10, 2020
Maximum K.E $= K_{max} = E - \phi$$\phi$ is the work function$K_{max}= \large\frac{hc}{\lambda} - \p...
0 votes
The value of coefficient of volume expansion of glycerin is $5 \times 10^{–4} K^{–1}$. The fractional change in the density of glycerin for a rise of $40^°C$ in its temperature, is :
answered Feb 10, 2020
$r = $ coefficient of volume expansion $= 5 \times 10^{-4}$$\delta = \delta_o (1+r \Delta T)$$\delta...
0 votes
In an astronomical telescope in normal adjustment a straight black line of length L is drawn on inside part of objective lens. The eye-piece forms a real image of this line. The length of the image is I. The magnification of the telescope is :
answered Feb 10, 2020
https://clay6.com/mpaimg/1778_a.jpg Length of object $= L$Length of image $=I$magnification of eye p...
0 votes
Water rises to a height ‘h’ in capillary tube. If the length of capillary tube above the surface of water is made less than ‘h’, then :
answered Feb 10, 2020
Since the height of water column is greater than length of tube water raises upto top of capillary t...
0 votes
A circuit contains an ammeter, a battery of 30 V and a resistance 40.8 ohm all connected in series. If the ammeter has a coil of resistance 480 ohm and a shunt of 20 ohm, the reading in the ammeter will be :
answered Feb 10, 2020
https://clay6.com/mpaimg/1777_a.jpg$R_{eq} = 40.8 + \begin{bmatrix} \large\frac{1}{\frac{1}{20} + \f...
0 votes
If dimensions of critical velocity $v_c$ of a liquid flowing through a tube are expressed as $[η^x ρ^y r^z]$ , where $η, ρ$ and $r$ are the coefficient of viscosity of liquid, density of liquid and radius of the tube respectively, then the values of $x, y,$ and $z$ are given by :
answered Feb 10, 2020
Critical velocity $V_c = \eta^x \; \delta^{^y} \; r^z$Using Dimensional Analysis$M^oL^1T^{-1} = (M^1...
0 votes
The input signal given to a CE amplifier having a voltage gain of 150 is $V_i = 2 \cos ( 15t + \frac{\pi}{3})$. The corresponding output signal will be :
answered Feb 10, 2020
$V_I = \text{Input voltage} = v_i = 2\cos[15t+\frac{\pi}{3}]$$A_V=\text{Voltage gain } = 150 =\frac{...
0 votes
A proton and an alpha particle both enter a region of uniform magnetic field B, moving at right angles to the field B. If the radius of circular orbits for both the particles is equal and the kinetic energy acquired by proton is 1MeV, the energy acquired by alpha particle will be :
answered Feb 10, 2020
Radius of the particle in magnetic field$\qquad R = \large\frac{mv}{qB}=\frac{\sqrt{2mE}}{qB}$$\qqua...
0 votes
The heart of a man pumps 5 liters of blood through the arteries per minute at a pressure of 150 mm of mercury. If the density of mercury be $13.6 \times 10^3 \;kg/m^3$ and $g = 10\; m/s^2$, then the power of heart in watt is :
answered Feb 10, 2020
Power = \frac{Work\; done}{time}$\qquad = \frac{mgh}{t} $$\qquad = \frac{v\; \eth\; g\; h }{t} \qqua...
0 votes
Two slits in Youngs experiment have widths in the ratio 1:25. The ratio of intensity at the maxima and minima in the interference pattern, $\frac{I_{max}}{I_{min}}$ is :
answered Feb 10, 2020
$\large\frac{I_{max}}{I_{min}} = \begin{bmatrix} \large\frac{\sqrt{\frac{I_1}{I_2}}+1 }{\sqrt{\frac...
0 votes
If potential(in volts) in a region is expressed as $V (x, y, z) = 6xy – y + 2yz$, the electric field (in N/C) at point (1, 1, 0) is :
answered Feb 10, 2020
Electric field $E = -(\large\frac{\partial v }{\partial x} \hat{i} + \frac{\partial v}{\partial y} \...
0 votes
On a frictionless surface, a block of mass $M$ moving at speed v collides elastically with another block of same mass M which is initially at rest. After collision the first block moves at an angle θ to its initial direction and has a speed $\frac{v}{3}$. The second block‘s speed after the collision is :
answered Feb 10, 2020
https://clay6.com/mpaimg/1776_a.jpgUsing conservation of $K.E$$\frac{1}{2}MV^2+0 = \frac{1}{2}M(\fra...
0 votes
A ball is thrown vertically downwards from a height of $20 m$ with an initial velocity $v_0$. It collides with the ground, loses 50 percent of its energy in collision and rebounds to the same height. The initial velocity $v_0$ is : (Take g = $10 ms^{–2}$)
answered Feb 10, 2020
The ball initially has $K.E+P.E$$50\%$ is last during impact$\frac{50}{100}(mgh+\frac{1}{2}mv^2)=mgh...
0 votes
An ideal gas is compressed to half its initial volume by means of several processes. Which of the process results in the maximum work done on the gas ?
answered Feb 10, 2020
https://clay6.com/mpaimg/1775_a.jpgAdiabatic has more area under the curve, therefore, this process...
0 votes
The coefficient of performance of a refrigerator is 5. If the temperature inside freezer is $–20^°C$, the temperature of the surroundings to which it rejects heat is :
answered Feb 10, 2020
Temperature of surrounding $= T_1$Temperature of freezer $= T_2 = -20^{\circ}c$$\qquad \qquad \qquad...
0 votes
Two stones of masses $m$ and $2 m$ are whirled in horizontal circles, the heavier one in a radius $\frac{r}{2}$ and lighter one in radius $r$. The tangential speed of lighter stone is $n$ times that of the value of heavier stone when they experience same centripetal forces. The value of $n$ is :
answered Feb 10, 2020
When they experience same centrepital force$\large\frac{m_1v_1^2}{r} = \frac{(2m)v_2^2}{r/2}$$\qquad...
0 votes
A plank with a box on it at one end is gradually raised about the other end. As the angle of inclination with the horizontal reaches 30°, the box starts to slip and slides 4.0 m down the plank in 4.0 s. The coefficients of static and kinetic friction between the box and the plank will be, respectively :
answered Feb 10, 2020
coefficient of friction $= \tan \alpha $$\mu_s = \tan 30 = \frac{1}{\sqrt 3}$$\qquad = 0.57 \approx ...
0 votes
A series R-C circuit is connected to an alternating voltage source. Consider two situations:
(a) When capacitor is air filled.
(b) When capacitor is mica filled.
Current through resistor is i and voltage across capacitor is V then :
answered Feb 10, 2020
Impedance of capacitor $\qquad X_C = \large\frac{1}{2\pi fc}$ $\qquad I = \large\frac{V...
0 votes
$4.0\; g$ of a gas occupies $22.4 \;liters$ at NTP. The specific heat capacity of the gas at constant volume is $5.0\; JK^{–1} mol^{–1}$. If the speed of sound in this gas at NTP is $952\; ms^{–1}$, then the heat capacity at constant pressure is (Take gas constant $R = 8.3 \;JK^{–1} mol^{–1}$)
answered Feb 10, 2020
Mass of gas $M = 4 \; gm$Volume $V = 22.4 \;lit$$\qquad C_V = 5\; J/mole\;K$$v = \text{Velocity of s...
0 votes
Light of wavelength 500 nm is incident on a metal with work function 2.28 eV. The de Broglie wavelength of the emitted electron is :
answered Feb 10, 2020
Energy $E = \large\frac{1240\;\;(eV)}{\lambda\;\;(nm)}$ $\qquad \qquad = \frac{1240}{500}$ ...
0 votes
Two metal wires of identical dimensions are connected in series. If $\sigma_1$ and $\sigma_2$ are the conductivities of the metal wires respectively, the effective conductivity of the combination is :
answered Feb 10, 2020
Requivalent $= R_1+R_2$$\implies \eth \frac{2L}{A} = \eth_1 \frac{L}{A} + \eth_2 \frac{L}{A} \qquad ...
0 votes
A nucleus of uranium decays at rest into nuclei of thorium and helium. Then :
answered Feb 8, 2020
$_{92}U^{238 } \to _{90}Th^{234} + 2 He^4$Since momentum is conserved $P_{thorium } = P_{Helium} = p...
0 votes
Two particles A and B, move with constant velocities $\overrightarrow{v_1}$ and $\overrightarrow{v_2}$. At the initial moment their position vectors are $\overrightarrow{r_1}$ and $\overrightarrow{r_2}$ respectively. the condition for particles A and B for their collision is :
answered Feb 8, 2020
https://clay6.com/mpaimg/1773_a.jpgFor the two to be particles to be collinear $\overrightarrow{R}=\...
0 votes
A force $\overrightarrow{F} = \alpha \hat{i} + 3 \hat {j} + 6 \hat{k}$ is acting at a point $\overrightarrow{r} = 2 \hat{i} -6\hat {j} - 12 \hat{k}$. The value of $\alpha$ for which angular momentum about origin is conserved is :
answered Feb 8, 2020
Angular momentum will be conserved when torque is zero.$\tau = \overrightarrow{r} \times \overrighta...
0 votes
At the first minimum adjacent to the central maximum of a single-slit diffraction pattern, the phase difference between the Huygen’s wavelet from the edge of the slit and the wavelet from the midpoint of the slit is :
answered Feb 8, 2020
For first minima, path difference between the two rays is $\lambda,$ at the first minima next to cen...
0 votes
Point masses $m_1$ and $m_2$ are placed at the opposite ends of a rigid rod of length $L$ and negligible mass. The rod is to be set rotating about an axis perpendicular to it. The position of point $P$ on this rod through which the axis should pass so that the work required to set the rod rotating with angular velocity $\omega_0$ is minimum, is given by :
answered Feb 8, 2020
$I = m_1x^2 + m_2(L-x)^2$For minima $\frac{dI}{dx} = 0$${\large\frac{dI}{dx}} = 2m_1x + 2xm_2 -2m_2L...
0 votes
A string is stretched between fixed points separated by 75.0 cm. It is observed to have resonant frequencies of 420 Hz and 315 Hz. There are no other resonant frequencies between these two. The lowest resonant frequency for this string is :
answered Feb 8, 2020
In stretched string Ratio of frequencies $315 :420 = 3:4$$\therefore 315$ is $3^{rd}$ harmonic$\;\;\...
0 votes
The position vector of a particle $\overrightarrow{R}$ as a function of time is given by :
$\overrightarrow{R} = 4 \sin (2 \pi t) \hat{i} + 4 \cos (2 \pi t) \hat{j}$
Where R is in meters, t is in seconds and $\hat{i}$ and $\hat{j}$ denote unit vectors along x- and y-directions, respectively. Which one of the following statements is wrong for the motion of particle ?
answered Feb 8, 2020
$\overrightarrow{R} = 4 \sin (2 \pi t) \hat{i} + 4 \cos (2 \pi t ) \hat {j}$$x^2+y^2= 4[\sin^2 (2 \p...
0 votes
A remote – sensing satellite of earth revolves in a circular orbit at a height of $0.25 \times 10^6\; m$ above the surface of earth. If earth’s radius is $6.38 \times 10^6\; m$ and $g = 9.8 \;ms^{–2}$, then the orbital speed of the satellite is :
answered Feb 8, 2020
Gravitational force = Centripetal force$\large\frac{GMm}{r^2}= \frac{mv^2}{r} \qquad where\;\;r = ...
0 votes
In the given figure, a diode D is connected to an external resistance R = 100 $\Omega$ and an e.m.f. of 3.5 V. If the barrier potential developed across the diode is 0.5V, the current in the circuit will be:
answered Feb 8, 2020
Current in the circuit$i = \large\frac{V_{net}}{R_{net}}$$\;\;\; = \large\frac{E- Barrier \;Potentia...
0 votes
A satellite S is moving in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth. Then,
answered Feb 8, 2020
Force on satellite is only gravitational force, which will always be towards the centre of earth.
0 votes
Two vessels separately contain two ideal gases A and B at the same temperature, the pressure of A being twice that of B. Under such conditions, the density of A is found to be $1.5$ times the density of B. The ratio of molecular weight of A and B is :
answered Feb 8, 2020
$P_A = 2P_B$$S_A = 1.5 S_B$Temperature is sameMolecular weight $M_w = \large\frac{SRT}{P}$$\qquad M_...
0 votes
A parallel plate air capacitor has capacity $‘C’$, distance of separation between plates is $‘d’$ and potential difference $‘V’$ is applied between the plates. Force of attraction between the plates of the parallel plate air capacitor is :
answered Feb 8, 2020
Force between the plates of capacitor having electric field $E$$F = qE$$\;\;\; = q (\large\frac{q}{2...
0 votes
A rectangular coil of length $0.12\; m$ and width $0.1\; m$ having $50$ turns of wire is suspended vertically in a uniform magnetic field of strength $0.2\; Weber/m^2$. The coil carries a current of $2A$. If the plane of the coil is inclined at an angle of $30^°$ with the direction of the field, the torque required to keep the coil in stable equilibrium will be :
answered Feb 8, 2020
Torque $= \tau$$\tau = NAIB \sin \theta$$\;\;\; = 50 \times 0.012 \times 2 \times 0.2 \times \sin 60...
0 votes
An automobile moves on a road with a speed of $54\; km\; h^{–1}$. The radius of its wheels is $0.45 \;m$ and the moment of inertia of the wheel about its axis of rotation is $3\; kg \;m^2$. If thevehicle is brought to rest in $15s$, the magnitude of average torque transmitted by its brakes to the wheel is :
answered Feb 8, 2020
Velocity $= 54 \;km/hr = 15\;m/s$$w_o \large\frac{V}{r} = \frac{15}{0.45} \frac{rad}{s}$Since wheel ...
0 votes
A source of sound S emitting waves of frequency $100 \;Hz$ and an observer O are located at some distance from each other. The source is moving with a speed of $19.4 ms^{-1}$ at an angle of $60^{A^°}$ with the source observer line as shown in the figure. The observer is at rest. The apparent frequency observed by the observer (velocity of sound in air $330 ms^{-1}$), is :
answered Feb 8, 2020
https://clay6.com/mpaimg/1772_a.jpg $n' = (\large\frac{V}{V- V_s \cos 60})n$$\;\;\;= 100 (\large\fra...
0 votes
If vectors $\overrightarrow{A} = \cos \omega \hat{i} + \sin \omega \hat{j} $ and $\overrightarrow{B} = \cos \frac{\omega t}{2} \hat{i} + \sin \frac{\omega t}{2} \hat{j} $ are functions of time, then the value of $t$ at which they are orthogonal to each other is :
answered Feb 8, 2020
$\overrightarrow{A}= \cos w t \;\hat{i} + \sin w t\; \hat{j}$$\overrightarrow{B} = \cos \frac{wt}{2}...
0 votes
A particle is executing a simple harmonic motion. Its maximum acceleration is $\alpha$ and maximum velocity is $\beta$. Then, its time period of vibration will be:
answered Feb 8, 2020
Maximum acceleration of $SHM$ is$\qquad \alpha = A w^2 --- (1)$Maximum velocity $\beta = Aw ---(2)$$...
0 votes
A potentiometer wire of length L and a resistance r are connected in series with a battery of e.m.f. $E_0$ and a resistance $r_1$. An unknown e.m.f. E is balanced at a length l of the potentiometer wire. The e.m.f. E will be given by :
answered Feb 8, 2020
https://clay6.com/mpaimg/1771_a.jpg$(AB = L)$Resistance of $AB = r$Current in wire $= \large\frac{E_...
0 votes
The Young’s modulus of steel is twice that of brass. Two wires of same length and of same area of cross section, one of steel and another of brass are suspended from the same roof. If we want the lower ends of the wires to be at the same level, then the weights added to the steel and brass wires must be in the ratio of :
answered Feb 8, 2020
Young modulu's Steel $Y_{steel} = 2 Y_{brass}$$\qquad L_s = L_b$ [same length]$\qquad A_s = A_b$ [sa...
0 votes
The cylindrical tube of a spray pump has radius R, one end of which has n fine holes, each of radius r. If the speed of the liquid in the tube is V, the speed of the ejection of the liquid through the holes is :
answered Feb 8, 2020
By equation of continuity $\qquad A_1V_1 = A_2V_2$$\qquad \;\;\;V_2 = \large\frac{A_1V_1}{A_2}$Radiu...
0 votes
An electron moves on a straight line path XY as shown. The abcd is a coil adjacent to the path of electron. What will be the direction of current, if any, induced in the coil ?
answered Feb 8, 2020
When negative charge $e^-$ is coming towards loop magnetic flux of one type increased and when going...
0 votes
The energy of the em waves is of the order of 15 keV. To which part of the spectrum does it belong ?
answered Feb 8, 2020
Energy $E = 15\;KeV $$\qquad \qquad = 15 \times 10^3 \;eV$Also $E = \large\frac{12400}{\lambda} \;e...
0 votes
In the spectrum of hydrogen, the ratio of the longest wavelength in the Lyman series to the longest wavelength in the Balmer series is :
answered Feb 8, 2020
${\large\frac{1}{\lambda } }= R Z^2\begin{bmatrix}\large\frac{1}{n_1^2} - \frac{1}{n_2^2} \end{bmatr...
Page:
Home Ask Tuition Questions
Practice
Your payment for is successful.
Continue
...