Recent questions in 1998-unused

asked Jun 15, 2018 by priyanka.c

0 answers

Which of the following gives most easily electrophilic substitution reaction :

asked Jun 15, 2018 by priyanka.c

1 answer

A cell 'A' with D.P.D. = 8 is surrounded by three cells 'B', 'C' and 'D' with D.P.D. respectively 4, 6 and 5. What shall be the direction of water movement :

asked Jun 15, 2018 by priyanka.c

0 answers

A point Q lies on the perpendicular bisector of an electrical dipole of dipole moment p. If the distance of Q from the dipole is r (much larger than the size of the dipole), then the electric field at Q is proportional to :

asked Oct 10, 2017 by priyanka.c

0 answers

A particle, with restoring force proportional to displacement and resisting force proportional to velocity is subjected to a force $F \sin ωt$. If the amplitude of the particle is maximum for $ω = ω_1$ and the energy of the particle maximum for $ω = ω_2$, then :

asked Oct 10, 2017 by priyanka.c

0 answers

We consider a thermodynamic system. If $\Delta U$ represents the increase in its internal energy and $W$ the work done by the system, which of the following statement is true?

asked Oct 10, 2017 by priyanka.c

2 answers

Common emitter circuit is used as amplifier, its current gain is 50. If input resistance is $1 K \Omega$ and input voltage is 5 volt then output current will be :

asked Oct 10, 2017 by priyanka.c

0 answers

The cause of potential barrier in a P-N junction diode is :

asked Oct 10, 2017 by priyanka.c

1 answer

Radiation energy corresponding to the temperature T of the sun is E. If its temperature is doubled, then its radiation energy will be :

asked Oct 10, 2017 by priyanka.c

0 answers

A rigid rod is placed against the wall as shown in figure. When its velocity of lower end is $10 \;ms^{-1}$ and its base makes an angle $\alpha = 60^{\circ}$ with horizontal, then the vertical velocity of its end B will be :

asked Oct 10, 2017 by priyanka.c

0 answers

For nuclear reaction : <br> $_{92}U^{235} + _0n^1 \to _{56}Ba^{144} + ......... + 3_0n^1$

asked Oct 10, 2017 by priyanka.c

0 answers

If a source moves perpendicularly from listener then the change in frequency will be

asked Oct 10, 2017 by priyanka.c

0 answers

Turn ratio of a step-up transformer is $1 : 25$. If current in load coil is $2A$, then the current in primary coil will be :

asked Oct 10, 2017 by priyanka.c

0 answers

Electric field at the equator of a dipole is E. If strength and distance is now doubled then the electric field will be :

asked Oct 10, 2017 by priyanka.c

0 answers

In the Bohr model of H-atom, an electron (e) is revolving around a proton (p) with velocity v, if r is the radius of orbit and m is mass and $\varepsilon_0$ is vacuum permittivity, the value of v is :

asked Oct 10, 2017 by priyanka.c

1 answer

A charge q is placed in an uniform electric field E. If it is released, then the K.E of the charge after travelling distance y will be :

asked Oct 10, 2017 by priyanka.c

0 answers

A car is moving with velocity V. If stop after applying break at a distance of 20 m. If velocity of car is doubled, then how much distance it will cover (travel) after applying break :

asked Oct 10, 2017 by priyanka.c

0 answers

O is the centre of an equilateral triangle ABC $F_1, F_2, F_3$ are three forces acting along the sides AB, BC and AC as shown in fig.What should be the magnitude of $F_3$ so that total torque about O is zero :

asked Oct 10, 2017 by priyanka.c

1 answer

Is $R_s$ is the equivalent resistance of n resistances in series and $R_p$ is the equivalent resistance of n resistances in parallel then $\frac{R_s}{R_p}$ is

asked Oct 10, 2017 by priyanka.c

0 answers