A moving coil ammeter is to be adapted to detect small alternating currents. Which of the diagrams shows how a diode could be connected in order to make the conversion?
Four persons A, B, C and Dare all moving on the same circular track with same constant speed in the anti-clockwise direction. At any instant they are located at the positions shown in figure, then the velocity of B, C and D as observed by A will have the respectively directions
In the arrangement shown, neglect the mass of the ropes and pulley. What must be the value of m to keep the system in equilibrium? There is no friction anywhere.
Figure shows a disc of mass M and radius R M hinged at the centre. A small ball of mass \[\frac{\text{M}}{2}\] is attached to point P with a thread of length 2R and held at rest at position shown. Now, the ball is released to fall under gravity. With what angular speed does the disc start turning when the string becomes taut?
An air-filled balloon floats in water with half of its volume submerged. To what depth inside water should it be taken so that it remains in equilibrium there? Take atmospheric pressure to be equal to 10 m of water-height
A particle executes SHM between \[x=-A\] to \[x=+A\]. The time taken for it to go from 0 to \[\frac{\text{A}}{\text{2}}\] is \[{{\text{T}}_{\text{1}}}\]and to go from \[\frac{\text{A}}{\text{2}}\] to A is \[{{\text{T}}_{\text{2}}}\]then \[\frac{{{\text{T}}_{\text{1}}}}{{{\text{T}}_{\text{2}}}}\]is
Equation of a longitudinal wave is given as \[y={{10}^{-2}}\sin 2\pi \left( 1000t+\frac{50x}{17} \right)\] (all SI units). At t = 0, change in pressure is maximum (in modulus) at \[x=\]
Two rods of same length and same area of cross section are joined. Temperature of two ends are as shown in figure. As we move along the rod, temperature are as shown in following:
A solid sphere having uniform charge density p and radius R is shown in figure. A spherical R cavity of radius \[\frac{R}{2}\] is hollowed out. What is potential of O? (Assuming potential at infinity to be zero)
Two concentric spherical shells of radii R and 2R have charges + Q and - Q. Which of the following may represent correct variation of potential with distance r from origin?
A capacitor is initially connected to a battery of EMF 3 V. At \[t=0,\] switch is thrown to B state. Now charge on capacitor at any instant is given by:
A conducting loop is being pulled with speed v from region I of magnetic field to region II. If resistance of the loop is R, current induced in the loop at the instant shown is:
When an a.c. source of e.m.f. \[E={{E}_{0}}\] sin 100 t is connected across a circuit, it is observed that voltage leads the current by a phase angle\[\frac{\pi }{4}\]. If the circuit consists possible only R-L, R-C or L-C in series the two elements could be:
Two blocks of mass, 1 kg and 2 kg are moving with velocities of \[\text{\hat{i}}\]and \[\text{4\hat{i}}\]respectively.
Statement-1: The kinetic energy of system appears minimum relative to an observer moving with a velocity of \[\text{3\hat{i}}\] m/s.
Statement-2: The kinetic energy of any 2 block system is \[\frac{1}{2}M{{V}_{c}}^{1}+\frac{1}{2}\mu V_{rel}^{2}\] where symbols have their usual meanings.
A)
Statement-1 is true, Statement-2 is true and Statement-2 is correct explanation for statement-1.
doneclear
B)
Statement-1 is true, Statement-2 is true and Statement-2 is NOT the correct explanation for statement-1.
A voltmeter with resistance \[500\,\Omega \] is used to measure the emf of a cell of internal resistance \[4\,\Omega \]. The percentage error in the reading of the voltmeter will be
Masses of neutron, proton and electron are 1.0087 U, 1.0073 u and 0.0005 u respectively. If a neutron decays into a proton and an electron, the energy released would be about
The figure shown the wavelength spectrum of X-rays produced when 50 keV electrons strike a molybdenum target. The \[{{\text{K}}_{\alpha }}\]line on the figure is represent by a number
A dentist wants a small mirror that when placed 2 cm from a tooth, will produce \[3\times \] upright image. What kind of mirror must be used and what must its focal length be?
Copper contains \[8.4\times {{10}^{28}}\] free electrons/\[{{m}^{3}}\]. A copper wire of cross-sectional area \[7.4\times {{10}^{-7}}\]\[{{m}^{2}}\] carries a current of 1 A. The electron drift speed is approximately:
100 ml of \[{{\text{H}}_{\text{2}}}{{\text{O}}_{\text{2}}}\] solution having volume strength 11.2 V is mixed with 50 ml of 0.5M Kl solution to liberate \[{{\text{I}}_{\text{2}}}\] gas. All the \[{{I}_{2}}\] gas liberated is trapped to form a 500 ml solution termed as X. 200 ml of the solution X of \[{{\text{I}}_{\text{2}}}\], required 50 ml hypo solution for conversion to \[{{\text{I}}^{\text{-}}}\]and \[{{\text{S}}_{\text{4}}}{{\text{O}}_{\text{6}}}^{\text{2-}}\]. Assuming all reactions to undergo 100% completion identify the incorrect option(s)
A)
Volume strength of remaining \[{{\text{H}}_{\text{2}}}{{\text{O}}_{\text{2}}}\] solution will be \[\frac{\text{78}\text{.4}}{\text{12}}\text{V}\].
doneclear
B)
Molarity of \[{{\text{I}}_{\text{2}}}\]in solution X is 0.025 M
A closed vessel initially contains a mixture of two gases \[{{A}_{2}}B\]and an in \[{{A}_{2}}B\]gas. During the thermal decomposition of gas A, B as per given \[{{A}_{2}}B(g)\to 2A(g)+B(g)\] the pressure changed from an initial value of 2 atm to 5.2 atm at the end of reaction. The rate constant (in min) if total pressure was measured as 4.8 atm after 10 min is-
1.7 gm of an ammonium salt were treated with 100 ml of normal \[NaOH\] solution and boiled till no more of ammonia gas was given off. The excess of \[NaOH\] solution left over required 60 ml of normal sulphuric acid. The % of ammonia in salt is-
Unknown salt \['A'+{{K}_{2}}C{{r}_{2}}{{O}_{7}}+\] cone. \[{{H}_{2}}S{{O}_{4}}\xrightarrow[{}]{{}}\] Reddish brown fumes. Which is the correct statement regarding the above observation
A)
It confirms the presence of \[C{{l}^{-}}\] ion
doneclear
B)
It confirms the presence of \[B{{r}^{-}}\] ion
doneclear
C)
It confirms the presence of both
doneclear
D)
It neither confirms \[C{{l}^{-}}\] nor \[B{{r}^{-}}\] unless it is passed through \[NaOH\] solution
1 mol Fe reacts completely with 0.7 mol of \[{{O}_{2}}\] to give a mixture of only \[FeO\And F{{e}_{2}}{{O}_{3}}.\] The mol ratio of \[F{{e}^{+3}}\] to\[F{{e}^{+2}}\] in product mixture is:
Suitable reagent(s) to convert acetyl chloride into acetaldehyde is / are: [a]\[Na-{{C}_{2}}{{H}_{5}}OH\] [b]\[NaB{{H}_{4}}\] [c]\[{{H}_{2}}/Pd-BaS{{O}_{4}}\] [d]\[LiAlH{{(CM{{e}_{3}})}_{3}}\]
If the number of Silicon atoms is restricted to 23 only, what would be the number of oxygen atoms and magnitude of negative charges respectively in the structure of Pyroxene (single chain Silicate)?
2 Litre 2 M aqueous \[CuS{{O}_{4}}\] is electrolyzed using platinum electrodes and \[2\times 96500\,C\] charge is passed through it then what would be new conc. of\[(C{{u}^{2+}})\]in solution.
A tangent to ellipse \[\frac{{{x}^{2}}}{25}+\frac{{{y}^{2}}}{16}=1\] at any point P meets the line \[x=0\] at point Q. Let R be the image of Q in the line \[y=x,\] then circle whose extremities of diameter are Q and R, passes through a fixed point, whose coordinate is
Any ordinate MP of ellipse \[\frac{{{x}^{2}}}{25}+\frac{{{y}^{2}}}{16}=1\]meets the auxiliary circle at Q, then locus of point of intersection of normal?s at P and Q 10 curves is
A variable line having intercepts e and e' on co-ordinate axes, where\[\frac{e}{2},\frac{e'}{2}\] are eccentricities of a hyperbola and its conjugate hyperbola, then the line touches the circle \[{{x}^{2}}+{{y}^{2}}={{r}^{2}}\] whose radius is or
The set of values of 'x' for which \[\underset{x\to \infty }{\mathop{\text{L}im}}\,\frac{1}{1+{{\left( \frac{4{{\tan }^{-1}}2x}{\pi } \right)}^{2n}}}\] (where \[n\in N\]) is a non-zero finite quantity, is
Let \[f(x)=\left\{ \begin{matrix} x+1; & x<1 \\ \lambda ; & x=1 \\ {{x}^{2}}-x+3; & x>1 \\ \end{matrix} \right.\] be a strictly increasing function at \[x=1\], then the set of values of \['\lambda '\] are
Let \[f(x)=2{{x}^{2}}-3(a+1){{x}^{2}}+6ax-12\]has maxima and minima at \[{{x}_{1}}\] and \[{{x}_{2}}\] respectively and if \[2{{x}_{1}}={{x}_{2}}\], then the value of 'a' is
If \[P=\underset{x\to \infty }{\mathop{\text{L}im}}\,\frac{{{\left( \coprod\limits_{r=1}^{n}{({{n}^{3}}+{{r}^{3}})} \right)}^{1/n}}}{{{n}^{3}}}\] and \[\lambda =\int\limits_{0}^{1}{\frac{dx}{1+{{x}^{3}}}}\] then \[\ln P\] is equal to
If \[\overrightarrow{a},\overrightarrow{b}\]and \[\overrightarrow{c}\]are non-coplanar vectors such That \[(x+y-3)\overrightarrow{a}+(2x-y+2)\overrightarrow{b}+(2x+y+\lambda )\overrightarrow{c}=\overrightarrow{0}\] holds true for some x and y then \[\lambda \] is
Let \[A=\left( \begin{matrix} {{x}^{2}} & 6 & 8 \\ 3 & {{y}^{2}} & 9 \\ 4 & 5 & {{z}^{2}} \\ \end{matrix} \right),\] \[B=\left( \begin{matrix} 2x & 3 & 5 \\ 2 & 2y & 6 \\ 1 & 4 & 2z-3 \\ \end{matrix} \right)\] be two matrices and if Tr. = Tr. , then the value of \[(x+y+z)\] is equal to
Consider line \[L\equiv \frac{x-1}{2}=\frac{y+1}{-3}=\frac{z+10}{8}\]. Point P (1, 0, 0) and Q are such that PQ is perpendicular to line L and the mid-point of PQ lies on the line L then Q is
The common tangent between\[~9{{x}^{2}}-16\text{ }{{y}^{2}}=144\]and \[~{{x}^{2}}+{{y}^{2}}=9\]cuts the coordinate axes at A and B, then the product OA-OB equals
Let \[f(x)=\frac{x-1}{4}+\frac{{{(x-1)}^{3}}}{12}+\frac{{{(x-1)}^{5}}}{20}+\frac{{{(x-1)}^{7}}}{28}\]?.\[\infty \] for \[x\in \] (0. 2), then \[f'\left( \frac{3}{2} \right)\] is equal to
Forces of magnitude 3 and 4 units act along \[6\hat{i}+2\hat{j}+3\hat{k}\] and \[3\hat{i}-2\hat{j}+6\hat{k}\] respectively on a particle and displaces it from (2, 2, -1) to (4, 3, 1), then the work done is