Recent questions in 2003

The physical quantities not having same dimensions are :

asked Dec 11, 2018 by pady_1

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An ammeter reads upto $1A$ . Its internal resistance is $0.81 \Omega$ . To increase the range to $10 \;A$ , the value of the required shunt is:

asked Dec 11, 2018 by pady_1

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A boy playing on the roof of a 10 m high building throws a ball with a speed of 10 m/s at an angle of $30^{\circ}$ with the horizontal. How far from the throwing point will the ball be at the height of $10 \;m$ from the ground ? [ $g = 10\; m/s^2, \; \sin 30^{\circ} = 1/2,\; \cos 30^{\circ} = \sqrt{3}/2]$

asked Dec 11, 2018 by pady_1

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A car moving with a speed of $50\; km/h$ , can be stopped by brakes after at least $6 \;m$ . If the same car is moving at a speed of $100\; km/h$ , the minimum stopping distance is :

asked Dec 11, 2018 by pady_1

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The difference in the variation of resistance with temperature in a metal and a semiconductor arises essentially due to the difference in the :

asked Dec 11, 2018 by pady_1

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Two spherical bodies of mass M and 5M and radii R and 2R respecitvely are released in free space with initial separation between their centres equal to 12 R. If they attract each other due to gravitational force only, then the distance covered by the smaller body just before collision is :

asked Dec 11, 2018 by pady_1

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When $U^{238}$ nucleus originally at rest, decays by emitting an alpha particle having a speed $u$ , the recoil speed of the residual nucleus is :

asked Dec 11, 2018 by pady_1

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Which of the following radiations has the least wavelength ?

asked Dec 11, 2018 by pady_1

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A particle performing uniform circular motion has angular momentum L. If its angular frequency is doubled and its kinetic energy halved, then the new angular momentum is :

asked Dec 11, 2018 by pady_1

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The time period of a satellite of earth is 5 hours. If the separation between the earth and the satellite is increased to 4 times the previous value, the new time period will become :

asked Dec 11, 2018 by pady_1

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A circular disc $X$ of radius $R$ is made from an iron plate of thickess $t$ , and another disc $Y$ of radius $4R$ is made from an iron plate of thickness $t/4$ . Then the relation between the moment of inertia $I_X$ and $I_Y$ is :

asked Dec 11, 2018 by pady_1

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Dimensions of $\frac{1}{\mu_0 \varepsilon_0}$ , where symbols have their usual meaning, are :

asked Dec 11, 2018 by pady_1

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The negative $Zn$ pole of Daniell cell, sending a constant current through a circuit, decreases in mass by $0.13\;g$ in $30$ minutes. If the electrochemical equivalent of $Zn$ and $Cu$ are $32.5$ and $31.5$ respectively, the increase in the mass of the positive $Cu$ pole in this time is :

asked Dec 11, 2018 by pady_1

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The thermo-emf of a thermocouple is $25 \; \mu V/^{\circ}C$ at room temperature. A galvanometer of $40 \Omega$ resistance, capable of detecting current as low as $10^{-5}A$ , is connected with the thermocouple. The smallest temperature difference that can be detected by this system is :

asked Dec 11, 2018 by pady_1

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Consider telecommunication through optical fibres. Which of the following statements is not true ?

asked Dec 11, 2018 by pady_1

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A strip of copper and another of germanium are cooled from room temperature to 80 K. The resistance of :

asked Dec 11, 2018 by pady_1

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The length of a wire of a potentiometer is 100 cm, and the emf of its stand and cell is E volt. It is employed to measure the emf of a battery whose internal resistance is $0.5 \Omega$ . If the balance point is obtained at $l = 30\; cm$ from the positive end, the emf of the battery is :

asked Dec 11, 2018 by pady_1

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A spring balance is attached to the ceiling of a lift. A man hangs his bag on the spring and the spring reads 49 N, when the lift is stationary. If the lift moves downward with an acceleration of 5 m/s, the reading of the spring balance will be :

asked Dec 11, 2018 by pady_1

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Curie temperature is the temperature above which :

asked Dec 11, 2018 by pady_1

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The magnetic lines of force inside a bar magnet :

asked Dec 11, 2018 by pady_1

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A magnetic needle lying parallel to a magnetic field requires $W$ unit of work to turn it through $60^{\circ}$ . The torque needed to maintain the needle in this position will be :

asked Dec 11, 2018 by pady_1

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A thin rectangular magnet suspended freely has a period of oscillation equal to $T$ . Now it is broken into two equal halves (each having half of the original length) and one piece is made to oscillate freely in the same field. If its period of oscillation is $T'$ , the ratio $T'/T$ is :

asked Dec 11, 2018 by pady_1

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A particle of charge $-16 \times 10^{-18} C$ moving with velocity $10\; ms^{-1}$ along the x-axis enters a region where a magnetic field of induction B is along the y-axis and an electric field of magnitude $10^4 V/m$ is along the negative z-axis. If the charged particle continues moving along the x-axis, the magnitude of B is :

asked Dec 11, 2018 by pady_1

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A particle of mass $M$ and charge $Q$ moving with velocity $\overrightarrow{v}$ describes a circular path of radius $R$ when subjected to a uniform transverse magnetic field of induction $B$ . The work done by the field when the particle completes one full circle is :

asked Dec 11, 2018 by pady_1

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