question_answer2) A galvanometer has current range of 15 mA and voltage range 750 mV. To convert this galvanometer into an ammeter of range 25 A, the required shunt is
question_answer3) The daniel cell is balanced on 125 cm length of a potentiometer. Now, the cell is ?short circuited by a resistance of 2\[\Omega \], and the balance is obtained at 100 cm. The internal resistance of the daniel cell is
question_answer4) Four resistances of 10\[\Omega \], 60\[\Omega \]., 100\[\Omega \]. and 200\[\Omega \]. respectively taken in order are used to form a Wheatstone's bridge. A 15V battery is connected to the ends of a 200\[\Omega \], resistance, the current through it will be
question_answer5) circuit has a self-inductance of 1 H and carries a current of 2A. To prevent sparking, when the circuit is switched off, a capacitor which can withstand 400 V is used. The least capacitance of capacitor connected across the switch must be equal to
question_answer7) A resistor of 6 \[k\Omega \] with tolerance 10% and another resistance of 4 \[k\Omega \] with tolerance 10% are connected in series. The tolerance of the combination is about
A)
5%
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B)
10%
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C)
12%
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D)
15% In series combination, \[=5000kW\] \[=\frac{mgh}{t}\] Error in combination \[=7.5\times 9.8\times 4.7\] \[=3454.5kW\] \[\text{=}\frac{\text{Power used}}{\text{Power consumed}}\text{ }\!\!\times\!\!\text{ 100}\] \[=\frac{3454.5}{5000}\times 100=69%\] = 10
question_answer9) A proton and an a-particle, accelerated through the same potential difference, enter a region of uniform magnetic field normally. If the radius of the proton orbit is 10 cm, then radius of a-particle is
question_answer10) An ammeter and a voltmeter of resistance R are connected in series to an electric cell of negligible internal resistance. Their reading are A and V respectively. If another resistance R is connected in parallel with the voltmeter, Then
question_answer11) A neutron is moving with velocity u. It collides head on and elastically with an atom of mass number A. If the initial kinetic energy of the neutron is E , then how much kinetic energy will be retained by the neutron after reflection?
question_answer12) If a magnet is suspended at angle 30° to the magnet meridian, the dip of needle makes angle of 45° with the horizontal, the real dip is
question_answer15) In hydrogen discharge tube, it is observed that through a given, cross-section \[3.31\times {{10}^{15}}\] electrons are moving from right to left and \[3.12\times {{10}^{5}}\] protons are moving from left to right. The current in the discharge tube and its direction will be
question_answer17) If 1000 droplets each of potential IV and radius r are mixed to form a big drop. Then, the potential of the drop as compared to small droplets, will be
question_answer18) A Zener diode, having breakdown voltage equal to 15 V is used in a voltage regulator circuit shown in figure. The current through the diode is
question_answer19) The activity of a radioactive sample is measured as \[{{N}_{0}}\]counts per minute at t = 0 and \[{{N}_{0}}/C\] counts per minute at t= 5 min. The time, (in minute) at which the activity reduces to half its value, is
question_answer20) If the electron in the hydrogen atom jumps from third orbit to second orbit, the wavelength of the emitted radiation in term of Rydberg constant is
question_answer21) Silver has a work function of 4.7 eV. When ultraviolet light of wavelength 100 nm is incident on it a potential of 7.7 V is required to stop the photoelectrons from reaching the collector plate. How much potential will be required to stop photoelectrons, when light of wavelength 200 nm is incident on it?
question_answer22) If the distance of 100 W lamp is increased from a photocell, the saturation current i in the photocell varies with the distance d as
question_answer25) When a resistor of 11\[\Omega \] is connected in series with an electric cell. The current flowing in it is 0.5 A. Instead when a resistor of 5\[\Omega \] is connected to the same electric cell in series, the current increases by 0.4 A. The internal resistance of the cell is
question_answer26) A battery is charged at a potential of 15 V in 8 h when the current flowing is 10A. The battery on discharge supplies a current of 5A for 15 h. The mean terminal voltage during discharge is 14V. The watt-hour efficiency of battery is
question_answer27) A circular current carrying coil has a radius R. The distance from the centre of the coil on the axis, where the magnetic induction will be \[\frac{1}{8}\]th to its value at the centre of the coil is
question_answer29) Two coils have a mutual inductance 0.55 H. The current changes in the first coil according equation \[I={{I}_{0}}\]sin wt. where, \[{{I}_{0}}=10A\] and \[\omega =100\pi \]rad/s. The maximum value of emfin the second coil is
question_answer30) An L-C-R circuit contains \[R=50\Omega ,\] L = 1 mH and \[C=0.\mu F.\]The impedance of the circuit will be minimum for a frequency of
question_answer31) An eye can detect \[5\times {{10}^{4}}\]photons per square metre per sec of green light \[\left( \lambda =5000\overset{\circ }{\mathop{\text{A}}}\, \right)\]while the ear can detect \[{{10}^{-13}}W/{{m}^{2}}.\]. The factor by which the eye is more sensitive as a power detector then the ear is close to
question_answer32) The amplification factor of a triode is 50. If the grid potential is decreased by 0.20 V. What increase, in plate potential will keep the plate current unchanged?
question_answer35) An installation consisting of an electric motor driving a water pump left 75 L of water per second to a height of 4.7 m. If the motor consumes a power of 5 kW, then the efficiency of the installation is
question_answer36) The potential difference across the terminals of a battery is 50 V when 11 A current is drawn and 60 V, when 1 A current is drawn. The emf and the internal resistance of the battery are
question_answer38) A metallic surface ejects electrons. When exposed to green light of intensity I but no photoelectrons are emitted, when exposed to yellow light of intensity 7. It is possible to eject electron from the same surface by
question_answer39) An electron moves at right angle to a magnetic field of\[5\times {{10}^{-2}}\] T with a speed of \[6\times {{10}^{7}}\]m/s. If the specific charge of the electron is \[1.7\times {{10}^{11}}C/kg.\]The radius of the circular path will be
question_answer40) A solenoid 30 cm long is made by winding 2000 loops of wire on an iron rod whose cross-section is 1.5 cm2. If the relative permeability of the iron is 6000. What is the self-inductance of the solenoid?
question_answer41) The standard molar heat of formation of ethane, \[\text{C}{{\text{O}}_{\text{2}}}\]and water (l) are respectively -21.1, -94.1 and - 68.3 kcal. The standard molar heat of combustion of ethane will be
question_answer42) The solubility product of \[\text{A}{{\text{g}}_{\text{2}}}\text{Cr}{{\text{O}}_{\text{4}}}\]is \[32\times {{10}^{-12}}.\] What is the concentration of \[\text{CrO}_{\text{4}}^{\text{-}}\] ions in that solution?
question_answer43) The equivalent conductivity of a solution containing 2.54 g of \[CuS{{O}_{4}}\] per L is \[91.0{{W}^{-1}}\]\[c{{m}^{2}}e{{q}^{-1}}.\] Its conductivity would be
question_answer44) The half-life of two samples are 0.1 and 08 s. Their respective concentration are 400 and 50 respectively. The order of the reaction is
question_answer48) In the reaction, \[8Al+3F{{e}_{3}}{{O}_{4}}\to 4A{{l}_{2}}{{O}_{3}}+9Fe\] the number of electrons transferred from the reluctant to the bxidant is
question_answer49) The bond angles of \[\text{N}{{\text{H}}_{\text{3}}}\text{,NH}_{\text{4}}^{\text{+}}\] and \[\text{NH}_{\text{2}}^{\text{-}}\] are in the order
question_answer50) A gaseous mixture containing He, \[C{{H}_{4}}\]and \[S{{O}_{2}}\] was allowed to effuse through a fine hole then find what molar ratio of gases coming out initially? (Given mixture contains He, \[C{{H}_{4}}\]and \[S{{O}_{2}}\] in 1 : 2 : 3 mole ratio).
question_answer53) The final product (IV) in the sequence of reactions \[\begin{align} & C{{H}_{3}}CHOH\xrightarrow{PB{{r}_{3}}}I\xrightarrow[Ether]{Mg} \\ & | \\ & C{{H}_{3}} \\ \end{align}\] ..
question_answer61) If the elevation in boiling point of a solution of 10 g of solute (mol. wt. = 100) in 100 g of water is \[\Delta {{T}_{b}},\]the ebullioscopic constant of water is
question_answer72) The sodium extract, of an organic compound on acidification with acetic acid and addition of lead acetate solution gives a black precipitate. The organic compound contains
question_answer75) A metal has bcc structure and the edge length of its unit cell is 3.04\[\overset{\circ }{\mathop{\text{A}}}\,\]. The volume of the unit cell in cm 3 will be
question_answer76) Among \[{{\left[ Fe{{\left( {{H}_{2}}O \right)}_{6}} \right]}^{3+}},\]\[{{\left[ Fe{{\left( CN \right)}_{6}} \right]}^{3-}},\] \[{{\left[ Fe{{\left( Cl \right)}_{6}} \right]}^{3-}}\]species, the hybridisation state of the Fe atom are, respectively.
question_answer78) The rate constant for forward reaction and backward reaction of hydrolysis of ester are \[1.1\times {{10}^{-2}}\] and \[1.5\times {{10}^{-3}}\]per minute respectively. Equilibrium constant for the reaction is \[C{{H}_{3}}COO{{C}_{2}}{{H}_{5}}+{{H}_{2}}O\rightleftharpoons C{{H}_{3}}COOH+{{C}_{2}}{{H}_{5}}OH\]
question_answer91) Two lines \[\frac{x-1}{2}=\frac{y+1}{3}=\frac{z-1}{4}\] and \[\frac{x-3}{1}=\frac{y-k}{2}=z\] intersect at a point, if k is equal to
question_answer93) The triangle formed by the tangent to the curve \[f\left( x \right)={{x}^{2}}+bx-b\] at the point (1, 1) and the coordinate axes lies in the first quadrant. If its area is 2, then the value of b is
question_answer98) The minimum area of the triangle formed by any tangent to the ellipse \[\frac{{{x}^{2}}}{{{a}^{2}}}+\frac{{{y}^{2}}}{{{b}^{2}}}=1\] with the coordinate axes is
question_answer99) If the line lx + my ? n = 0 will be a normal to the hyperbola, then \[\frac{{{a}^{2}}}{{{l}^{2}}}-\frac{{{b}^{2}}}{{{m}^{2}}}=\frac{{{\left( {{a}^{2}}+{{b}^{2}} \right)}^{2}}}{k},\] where k is equal to
question_answer102) The angle between lines joining the origin to the point of intersection of the line \[\sqrt{3}x+y=2\] and the curve \[{{y}^{2}}-{{x}^{2}}=4\] is
question_answer103) If the area of the triangle on the complex plane formed by the points z, z + iz and iz is 200, then the value of 3 |z| must be equal to
question_answer105) If a plane meets the coordinate axes at A, B and C such that the centroid of the triangle is (1, 2, 4) then equation of the plane is
question_answer109) If l (m. n) = \[\int_{0}^{1}{{{t}^{m}}{{\left( 1+t \right)}^{n}}dt,}\] then the expression for l (m, n) in terms of l (m + n + 1) is
question_answer115) The length of longer diagonal of the parallelogram constructed on 5a+2b and a -3b, if it is given that \[\left| a \right|=2\sqrt{2},\left| b \right|=3\]and the angle between a and b is \[\frac{\pi }{4},\] is
question_answer118) If the integers m and n are chosen at random from 1 to 100, then the probability that a number of the form \[{{7}^{n}}+{{7}^{m}}\] is divisible by 5, equals to