Recent questions and answers in 1999

For moon, its mass is 1/81 of earth mass and its diameter is 1/3.7 of earth dia.If acceleration due to gravity at earth surface is $9.8 m/s ^{2}$ then at moon its value is :

answered Apr 14, 2020 by meena.clay6

1 answer

On the basis of unit cell concept a crystal has :

answered Sep 13, 2019 by meena.clay6

1 answer

In compound microscope the magnification is 95, and the distance of object from objective lens 1/3.8 cm and focal length of objective is ¼ cm. What is the magnification of eye pieces when final image is formed at least distance of distinct vision :

answered Sep 13, 2019 by meena.clay6

1 answer

Two particles are projected with same initial velocity one makes angle ? with horizontal while other makes an angle ? with vertical. If their common range is R then product of their time of flight is directly proportional to :

answered Sep 12, 2019 by meena.clay6

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Frequency of an E.M. waves is 10 MHz then its wavelength is :

answered Sep 12, 2019 by meena.clay6

1 answer

When a stick is released (as shown in fig.). Its free end velocity when it strikes the ground is : l = 0.6m Hinge (ground)

answered Sep 12, 2019 by meena.clay6

1 answer

For a body angular velocity $\overrightarrow{\omega}=\widehat{i}-2\widehat{j}+3\widehat{k}$ and radius vector is $\overrightarrow{r}=\widehat{i}+\widehat{j}+\widehat{k}$ then its velocity is :

answered Sep 12, 2019 by meena.clay6

1 answer

When a spring is subjected to 4N force its length is a metre and if 5N is applied length is b metre. If 9N is applied its length is :

answered Sep 12, 2019 by meena.clay6

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If radius of earth shrinks by 1% then for acceleration due to gravity :

answered Sep 12, 2019 by meena.clay6

1 answer

Rohini satellite is at a height of 500 km. and Insat-B is at a height of 3600 km. from surface of earth then relation between their orbital velocity ( $V_R$ , $V_1$ ) is :

answered Sep 12, 2019 by meena.clay6

2 answers

A particle starts from rest with constant acceleration. The ratio of space-average velocity to the time average velocity is :

answered Sep 12, 2019 by meena.clay6

1 answer

Two conducting slabs of heat conductivity $K_1$ and $K_2$ are joined as shown in fig. The temp. at ends of the slabs are $\theta_1$ and $\theta_2({\theta_1}>{\theta_2})$ the, final temp. ( $\theta_m$ ) of junction is : <br>

answered Sep 12, 2019 by meena.clay6

1 answer

For a prism its refractive index is cot A/2 then minimum angle of deviation is :

answered Sep 12, 2019 by meena.clay6

1 answer

The half life of a radio nuclide is 77 days then its decay constant is :

answered Sep 12, 2019 by meena.clay6

1 answer

A radio-active elements emits one $\alpha$ and $\beta$ particles then mass no. of daughter element is :

answered Sep 12, 2019 by meena.clay6

1 answer

Two identically charged particles A and B initially at rest, are accelerated by a common potential difference V. They enters into a transverse uniform magnetic field B. They describe a circular path of radii $r_1$ and $r_2$ respectively then their mass ratio is :

answered Sep 12, 2019 by meena.clay6

1 answer

The total energy of an electron is 3.555 MeV, then its Kinetic energy is :

answered Sep 12, 2019 by meena.clay6

1 answer

The K.E. of electron and photon is same then relation between their De-Broglie wavelength :

answered Sep 12, 2019 by meena.clay6

1 answer

The truth table for the following network is :

answered Sep 12, 2019 by meena.clay6

1 answer

Frequency of simple pendulum in a free falling lift is -

answered Sep 6, 2019 by meena.clay6

1 answer

A spring elongated by length 'L' when a mass 'M' is suspended to it. Now a tiny mass 'm' is attached and then released, its time period of oscillation is -

answered Sep 6, 2019 by meena.clay6

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Two springs A and B $(K_A = 2 K_B)$ are stretched by same suspended weights then ratio of workdone in stretching is -

answered Sep 6, 2019 by meena.clay6

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The amplitude of a S.H.O. reduces to 1/3 in first 20 secs. then in first 40 sec. its amplitude becomes -

answered Sep 6, 2019 by meena.clay6

1 answer

A particle is projected with velocity 'u' makes an angle $\theta w.r.t$ horizontal. Now it breaks in two identical parts at highest point of trajectory. If one part is retrace its path, then velocity of other part is -

answered Sep 6, 2019 by meena.clay6

1 answer

A sphere maintained at temperature 600 K, has cooling rate R in an external environment of 200 K temp. If its temp. falls to 400 K then its colling rate will be -

answered Sep 5, 2019 by meena.clay6

1 answer

Initial pressure and volume of a gas are P and V respectively. First its volume is expanded to 4V by isothermal process and then again its volume makes to be V by adiabatic process then its final pressure is ( $\gamma=1.5$ ) -

answered Sep 5, 2019 by meena.clay6

1 answer

A cylindrical tube (L = 125 cm) is resonant with a tuning fork of frequency 330 Hz. If it is filling by water then to get resonance again, minimum length of water column is $(V_{air} = 330 m/s)$ -

answered Sep 5, 2019 by meena.clay6

1 answer

Depletion layer has (for an unbiased PN junction) -

answered Sep 5, 2019 by meena.clay6

2 answers

For a vibration magnetometer, the time period of suspended bar magnet can be reduced by -

answered Sep 4, 2019 by meena.clay6

1 answer

In millikan oil drop experiment a charged drop falls with a terminal velocity V. If an electric field E is applied vertically upwards it moves with terminal velocity 2V in upward direction. If electric field reduces to E/2 then its terminal velocity will be -

answered Sep 4, 2019 by meena.clay6

2 answers

The terminal potential difference of a cell is greater than its emf when -

answered Sep 4, 2019 by meena.clay6

1 answer

For a inductor coil L = 0.04 H, then workdone by source to establish a current of 5A in it is -

answered Sep 4, 2019 by meena.clay6

2 answers

Eight equals charged tiny drops are combined to form a big drop. If the potential on each drop is 10V then potential of big drop will be -

answered Sep 4, 2019 by meena.clay6

1 answer

Initially plane of coil is parallel to the uniform magnetic field B. In time $\Delta{t}$ it makes to perpendicular to the magnetic field, then charge flows in $\Delta{t}$ depends on this time as -

answered Sep 4, 2019 by meena.clay6

1 answer

The value of R for which power in it is maximum-

answered Sep 4, 2019 by meena.clay6

1 answer

If the power dissipated in $5\Omega$ is 20 W then power dissipated in $4 \Omega$

answered Sep 4, 2019 by meena.clay6

1 answer

The dipole moment of compound AB is 10.92 D and that of compound CD is 12.45 D. The bond length AB is $2.72 \mathring{A}$ and that of CD is $2.56 \mathring{A}$ then for these compound true statement is :

answered Sep 4, 2019 by sharmaaparna1

1 answer

The effective capacity of the network between terminals A and B is

answered Sep 4, 2019 by meena.clay6

1 answer

The current in $8\Omega$ resistance is (See fig.)

answered Sep 4, 2019 by meena.clay6

1 answer

Half life of a substance is 77 days then its decay constant will be :

answered Sep 3, 2019 by sharmaaparna1

1 answer

The bombarment of $\alpha$ -particle on $_{7}N^{14}$ , emits proton then new atom will be :

answered Sep 3, 2019 by sharmaaparna1

1 answer

Which of the following reaction given by isocyanide :

answered Sep 3, 2019 by sharmaaparna1

1 answer

Clemenson's reaction is :

answered Sep 3, 2019 by sharmaaparna1

1 answer

Which of the following is true for a reaction in which all the reactant & product are liquids :

answered Sep 3, 2019 by sharmaaparna1

1 answer

A system is expanded under adiabatic process :

answered Sep 3, 2019 by sharmaaparna1

1 answer

Increasing order of bond length is :

answered Sep 3, 2019 by sharmaaparna1

1 answer

What is true for a cyclic process :

answered Sep 3, 2019 by sharmaaparna1

1 answer

What will be the $H^+$ con when 4 gm NaOH dissolved in 1000 ml. of water :

answered Sep 3, 2019 by sharmaaparna1

1 answer

Sucrose on hydrolysis gives :

answered Sep 3, 2019 by sharmaaparna1

1 answer

Cr in $[Cr(NH_3)_6]$ has number of unpaired electron :

answered Sep 3, 2019 by sharmaaparna1

1 answer

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