Recent questions tagged 42

The major product of the following reaction is :

asked Jul 8, 2019 by pady_1

0 answers

The photoelectric work function of a metal surface is $2\;eV$. When light of frequency $1.5 \times 10^{15} Hz$ is incident on it, the maximum kinetic energy of the photo electrons, approximately is :

asked Dec 19, 2018 by pady_1

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In a meter bridge the gaps are closed by resistance 2 and 3 ohm. The value of shunt to be added to 3 ohm resistor to shift the balancing point by 22.5 cm is :

asked Dec 19, 2018 by pady_1

0 answers

During an adiabatic process, if the pressure of an ideal gas is proportional to the cube of its temperature the ratio $\gamma = \frac{c_p}{c_v}$ is : (Specific heat at constant volume = $c_v$ specific heat at constant pressure = $c_p$ )

asked Dec 19, 2018 by pady_1

0 answers

From a uniform wire, two circular loops are made (i) $P$ of radius $'r'$ and (ii) $Q$ of radius $nr$. If the moment of inertia of $Q$about an axis passing through its centre and perpendicular to its plane is 8 times that of $P$ about a similar axis, the value of $'n$ is (diameter of the wire is very much smaller than $i$ or $nr$ ) :

asked Dec 11, 2018 by pady_1

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When temperature increases, the frequency of a tuning fork :

asked Dec 11, 2018 by pady_1

0 answers

The core of any transformer is laminated so as to :

asked Dec 11, 2018 by pady_1

0 answers

The Boolean expression $\sim (p \lor q) \lor (\sim p \land q)$ is equivalent to :

asked Dec 11, 2018 by pady_1

1 answer

A magnetic needle of magnetic moment $6.7 \times 10^{-2} \; Am^2$ and moment of inertia $7.5 \times 10^{-6} kg\;m^2$ is performing simple harmonic oscillations in a magnetic field of $0.001\; T$. Time taken for $10$ complete oscillations is :

asked Dec 11, 2018 by pady_1

0 answers

Which one of the following ores is best concentrated by froth floatation method ?

asked Dec 11, 2018 by pady_1

0 answers

In the isolation of metals, calcination process usually results in :

asked Dec 11, 2018 by pady_1

0 answers

If $g$ is the inverse of a function $f$ and $f'(x) = \frac{1}{1+x^5}$ , then $g'(x)$ is equal to

asked Dec 11, 2018 by pady_1

1 answer

Consider : Statement -I : $(P \wedge \sim q ) \wedge ( \sim p \wedge q )$ is a fallacy. Statement-II : $(p \to q) \leftrightarrow ( \sim q \to \sim p)$ is a tautology.

asked Dec 11, 2018 by pady_1

1 answer

A particle of mass m is at rest at the origin at time t=0. It is subjected to a force $F(t) = F_0e^{-bt}$ in the $x$ direction. Its speed v(t) is depicted by which of the following curves ?

asked Dec 11, 2018 by pady_1

0 answers

A man saves Rs. 200 in each of the first three months of his service. In each of the subsequent months his saving increases by Rs. 40 more than the saving of immediately previous month. His total saving from the start of service will be Rs. 11040 after

asked Dec 11, 2018 by pady_1

0 answers

A radioactive nucleus (initial mass number A and atomic number Z) emits 3 $\alpha$ particles and 2 positrons. The ratio of number of neutrons to that of protons in the final nucleus will be

asked Dec 11, 2018 by pady_1

0 answers

The half life period of a first order chemical reaction is 6.93 minutes. The time required for the completion of 99% of the chemical reaction will be (log 2 = 0.301) :

asked Nov 29, 2018 by pady_1

0 answers

Larger number of oxidation states are exhibited by the actinoids than those by the lanthanoids, the main reason being

asked Nov 29, 2018 by pady_1

0 answers

In an AC circuit the voltage applied is $E= E_0 \sin \omega t$. The resulting current in the circuit is $I = I_0 \sin (\omega t - \frac{\pi}{2})$. The power consumption in the circuit is given by :

asked Nov 29, 2018 by pady_1

0 answers

The 'rad' is the correct unit used to report the measurement of :

asked Nov 13, 2018 by pady_1

0 answers

The area enclosed between the curve $y= \log_e (x+e)$ and the co-ordinate axes is :

asked Nov 5, 2018 by pady_1

0 answers

The diagram shows the energy levels for an electron in a certain atom. Which transition shown represents the emission of a photon with the most energy ?

asked Nov 5, 2018 by pady_1

0 answers

The area of the region bounded by the curves $y = |x-2|, \; x=1, \;x=3$ and the $x-axis$ is

asked Nov 5, 2018 by pady_1

0 answers

An electron of mass m with an initial velocity $\overrightarrow{V} = V_0 \hat{i} (V_0 > 0) $ enters an electric field $\overrightarrow{E} = -E_0 \hat{i} (E_0 = constant > 0)$ at $t = 0$. If $\lambda_0$ is its de-Broglie wavelength initially, then its de-Broglie wavelength at time t is :

asked Aug 21, 2018 by pady_1

1 answer

Which one is the correct order of acidity ?

asked Aug 21, 2018 by pady_1

1 answer

Which of the following biphenyls is optically active ?

asked Aug 21, 2018 by pady_1

2 answers

Method by which Aniline cannot be prepared is -

asked Aug 21, 2018 by pady_1

1 answer

The Binding energy per nucleon of $_3^7Li$ and $_2^4 He$ nucleon are 5.60 MeV and 7.06 MeV, respectively. In the nuclear reaction $_3^7Li + _1^1 He \to _2^4 He + _2^4 He + Q, $ the value of energy $Q$ released is :

asked Aug 20, 2018 by pady_1

1 answer

A parallel beam of fast moving electrons is incident normally on a narrow slit. A fluorescent screen is placed at a large distance from the slit. If the speed of the electrons is increased, which of the following statements is correct ?

asked Aug 20, 2018 by pady_1

1 answer

Electron in hydrogen atom first jumps from third excited state to second excited state and then from second excited to the first excited state. The ratio of the wavelengths $\lambda_1 : \lambda_2$ emitted in the two cases is

asked Aug 20, 2018 by pady_1

1 answer

In the Davisson and Germer experiment, the velocity of electrons emitted from the electron gun can be increased by :

asked Aug 16, 2018 by pady_1

1 answer

A vibration magnetometer placed in magnetic meridian has a small bar magnet. The magnet executes oscillations with a time period of 2 sec in earth's horizontal magnetic field of 24 microtesla. When a horizontal field of 18 microtesla is produced opposite to the earth's field by placing a current carrying wire, the new time period of magnet will be –

asked Jul 26, 2018 by pady_1

1 answer

The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter is an :

asked Jul 26, 2018 by pady_1

0 answers

Two radioactive materials $X_1$ and $X_2$ have decay constants $5\lambda$ and $\lambda$ respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of $X_1$ to - that of $X_2$ will be $\frac{1}{e}$ after a time

asked Jul 26, 2018 by pady_1

1 answer

If the nucleus $^{27}_{13}Al$ has a nuclear radius of about 3.6 fm, the $^{125}_{52}Te$ would have its radius approximately as :-

asked Jul 26, 2018 by pady_1

1 answer

A convex lens and a concave lens, each having same focal length of 25 cm, are put in contact to form a combination of lenses. The power in dipoters of the combination is:-

asked Jul 25, 2018 by pady_1

2 answers

If the angle between the vector $\overrightarrow{A} \overrightarrow{B}$ is $\theta$the value of the product $(\overrightarrow B \times \overrightarrow A).\overrightarrow A)$ is equal to -

asked Jul 24, 2018 by pady_1

1 answer

The Bohr model of atoms :-

asked Jul 24, 2018 by pady_1

1 answer

A n-p-n transistor conducts when

asked Jul 24, 2018 by pady_1

1 answer

A capacitor of capacity $C_1$ charged upto V volt and then connected to an uncharged capacitor $C_2$. Then final P.D. across each will be

asked Jul 23, 2018 by pady_1

0 answers

Among which the magnetic susceptibility does not depend on the temperature : -

asked Jul 20, 2018 by pady_1

1 answer

A tall man of height 6 feet, want to see his full image. Then required minimum length of the mirror will be :

asked Jul 20, 2018 by pady_1

2 answers

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

asked Jun 15, 2018 by pady_1

1 answer

Harsh has 7 pair of black socks and 9 pair of red socks. All the socks are in a bag, if Harsh picks the socks without looking at them, how many socks he has to remove from the bag before he can be sure that he has a pair of a single color ?

asked Dec 31, 2015 by pady_1

0 answers

The number of lines of a symmetry in a protractor is

asked Dec 31, 2015 by pady_1

1 answer

Vinayak's father gave him Rs.134 to spend. He spent Rs.51.25 to buy some toys and Rs.40.07 to buy some books. How much does he have left?

asked Dec 31, 2015 by pady_1

0 answers

91 $\div \large\frac{91}{34}$

asked Dec 31, 2015 by pady_1

0 answers

The Greenville Secondary School canteen goes through a lot of peanut butter. Currently, they have 2,191 grams of regular peanut butter in stock. They also have 1,844 grams of crunchy peanut butter. How many grams do they have in total?

asked Dec 31, 2015 by pady_1

0 answers

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