Recent questions tagged 45

The method used to remove temporary hardness of water is :

asked Jul 8, 2019 by pady_1

2 answers

When $_{15}P^{30}$ decays to become $_{14}Si^{30}$ the particle released is :

asked Dec 19, 2018 by pady_1

0 answers

In a photoelectric experiment, the maximum velocity of photoelectrons emitted :

asked Dec 19, 2018 by pady_1

0 answers

The liquids at temperature $60^{\circ}C$ and $30^{\circ}C$ respectively have masses in the ratio $3:4$ and their specific heats in the ratio $4:5$. If the two liquids are mixed, the resultant temperature is :

asked Dec 19, 2018 by pady_1

0 answers

A body is executing simple harmonic motion. At a displacement $x$ its potential energy is $E_1$ and at a displacement $y$ its potential energy is $E_2$. The potenital energy $(E)$ at displacement $(x+y)$ is :

asked Dec 11, 2018 by pady_1

0 answers

The part of a transistor which is most heavily doped to produce large number of majority carries is :

asked Dec 11, 2018 by pady_1

0 answers

A nucleus with Z = 92 emits the following in a sequence : $\alpha, \; \alpha, \; \beta^-, \; \beta^-,\; \alpha,\; \alpha,\; \alpha, \; \alpha; \; \beta^-,\; \beta^-,\; \alpha,\; \beta^+, \; \beta^+, \; \alpha$. The $Z$ of the resulting nucleus is :

asked Dec 11, 2018 by pady_1

0 answers

The sum of the co-effiicients of all odd degree terms in the expansion of $(x + \sqrt{x^3-1})^5 + (x-\sqrt{x^3 - 1})^5, (x>1)$ is :

asked Dec 11, 2018 by pady_1

1 answer

A time dependent force F = 6t acts on a particle of mass 1kg. If the particle starts from rest, the work done by the force during the first 1 sec. will be :

asked Dec 11, 2018 by pady_1

0 answers

The reaction of zinc with dilute and concentrated nitric acid, respectively, produces :

asked Dec 11, 2018 by pady_1

0 answers

The least number of oxyacids are formed by :

asked Dec 11, 2018 by pady_1

0 answers

Let $\alpha$ and $\beta$ be the roots of equation $px^2 + qx + r = 0,\; p \neq 0$. If $p, q, r$ are in A.P. and $\frac{1}{\alpha} + \frac{1}{\beta} = 4$, then the value of $|\alpha - \beta|$ is

asked Dec 11, 2018 by pady_1

1 answer

The real number $k$ for which the equation, $2x^3 + 3x+ k = 0$ has two distinct real roots in $[0, 1]$

asked Dec 11, 2018 by pady_1

1 answer

A boy can throw a stone up to a maximum height of 10 m. The maximum horizontal distance that the boy can throw the same stone up to will be

asked Dec 11, 2018 by pady_1

0 answers

If $\overrightarrow{a} = \frac{1}{\sqrt{10}} (3 \hat{i} + \hat{k})$ and $\overrightarrow{b} =\frac{1}{7} (2 \hat{i} + 3 \hat{j} - 6\hat{k})$, then the value of $(2 \overrightarrow{a} - \overrightarrow{b} ) . [ (\overrightarrow{a} \times \overrightarrow{b} ) \times (\overrightarrow{a} + \overrightarrow{2b} ) ]$ is

asked Dec 11, 2018 by pady_1

0 answers

A diatomic ideal gas is used in a Car engine as the working substance. If during the adiabatic expansion part of the cycle, volume of the gas increases from V to 32V the efficiency of the engine is

asked Dec 11, 2018 by pady_1

0 answers

Copper crystallizes in fcc wih a unit cell length of 361 pm. What is the radius of copper atom ?

asked Nov 29, 2018 by pady_1

0 answers

For a reaction $\frac{1}{2}\rightarrow 2B$ rate of disappearance of ‘A’ is related to the rate of appearance of ‘B’ by the expression

asked Nov 29, 2018 by pady_1

0 answers

An ideal coil of 10 H is connected in series with a resistance of $5 \Omega$ and a battery of $5 V$. 2 s after the connection is made, the current flowing ( in ampere) in the circuit is :

asked Nov 29, 2018 by pady_1

0 answers

A force of $-F \hat{k}$ acts on O, the origin of the co-ordinate system. The torque about the point $(1, -1)$ is :

asked Nov 13, 2018 by pady_1

0 answers

The distance between the line $\overrightarrow{r} = 2 \hat{i} - 2 \hat{j} + 3 \hat{k} + \lambda (\hat{i} - \hat{j} + 4 \hat{k}) $ and the plane $\overrightarrow{r} . (\hat{i} + 5 \hat{j} + \hat{k}) = 5$ is :

asked Nov 5, 2018 by pady_1

0 answers

In a full wave rectifier circuit operating from 50 Hz mains frequency, the fundamental frequency in the ripple would be :

asked Nov 5, 2018 by pady_1

0 answers

Let $A(2, -3) $ and $B(-2, 1)$ be vertices of a triangle ABC. If the centroid of this triangle moves on the line $2x+3y=1$, then the locus of the vertex C is the line

asked Nov 5, 2018 by pady_1

0 answers

When the light of frequency $2v_o$ (where $v_0$ is threshold frequency), is incident on a metal plate, the maximum velocity of electrons emitted is $v_1$. When the frequency of the incident radiation is increased to $5v_0$, the maximum velocity of eletrons emitted from the same plate is $v_2$. The ratio of $v_1$ to $v_2$ is

asked Aug 21, 2018 by pady_1

1 answer

Which of the following reactions is appropriate for converting acetamide to methanamine ?

asked Aug 21, 2018 by pady_1

1 answer

The rate of a first order reaction is $0.04 \; mol\; l^{-1} s^{-1}$ at 10 seconds and $0.03 \; mol\; l^{-1}\; s^{-1}$ at 20 seconds after initiation of the reaction. The half-life period of the reaction is :

asked Aug 21, 2018 by pady_1

1 answer

In the extraction of copper from its sulphide ore, the metal is finally obtained by the reduction of cuprous oxide with -

asked Aug 21, 2018 by pady_1

1 answer

The barrier potential of a p-n junction depends on : (a) type of semi conductor material (b) amount of doping (c) temperature Which one of the following is correct?

asked Aug 20, 2018 by pady_1

1 answer

The output (X) of the logic circuit shown in figure will be -

asked Aug 20, 2018 by pady_1

1 answer

A mixture consists of two radioactive materials $A_1$ and $A_2$ with half lives of $20\; s$ and $10\;s$ respectively. Initially the mixture has $40 \;g$ of $ A_1$ and $160\; g$ of $A_2$. The amount of the two in the mixture will become equal after :

asked Aug 20, 2018 by pady_1

1 answer

Fusion reaction takes place at high temperature because :

asked Aug 16, 2018 by pady_1

1 answer

A square surface of side L meter in the plane of the paper is placed in a uniform electric field E (volt/m) acting along the same plane at an angle $\theta$ with the horizontal side of the square as shown in figure. The electric flux linked to the surface, in units of volt-m, is

asked Jul 26, 2018 by pady_1

1 answer

In the nuclear decay given below : The particles emitted in the sequence are :

asked Jul 26, 2018 by pady_1

2 answers

Two thin lenses of focal lengths $f_1$ and $f_2$ are in contact and coaxial. The power of the combination is -

asked Jul 26, 2018 by pady_1

1 answer

Two radioactive substances A and B have decay constants $5 \lambda$ and $\lambda $ respectively. At $t=0$ they have the same number of nuclei. The ratio of number of nuclei of A to those of B will be $(\frac{1}{e} )^2$ after a time interval :-

asked Jul 26, 2018 by pady_1

1 answer

A car runs at a constant speed on a circular track of radius 100 m, taking 62.8 seconds for every circular lap. The average velocity and average speed for each circular lap respectively is:

asked Jul 25, 2018 by pady_1

1 answer

Application of a forward bias to a p-n junction -

asked Jul 24, 2018 by pady_1

1 answer

A coil of 40 henry inductance is connected in series with a resistance of 8 ohm and the combination is joined to the terminals of a 2 volt battery. The time constant of the circuit is :-

asked Jul 24, 2018 by pady_1

1 answer

If a full wave rectifier circuit is operating from 50 Hz mains, the fundamental frequency in the ripple will be :

asked Jul 24, 2018 by pady_1

1 answer

The magnetic field of given length of wire for single turn coil at its centre is 'B' then its value for two turns coil for the same wire is : -

asked Jul 23, 2018 by pady_1

1 answer

In BCC, the distance between two nearest atoms will be : -

asked Jul 20, 2018 by pady_1

1 answer

The correct relation for $\alpha$ , $\beta$ for a transistor :

asked Jul 20, 2018 by pady_1

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 Jun 15, 2018 by pady_1

1 answer

Which of following is correct ?

asked Dec 31, 2015 by pady_1

1 answer

Omar is planning the menu for a dinner party. He wants to serve one main dish and one salad. For the main dish, he can make steak or pasta. For the salad, Omar knows how to make macaroni salad, coleslaw, or spinach salad. How many different menu combinations can Omar serve?

asked Dec 31, 2015 by pady_1

0 answers

The perimeter of a film screen is 72 metres. It is 25 metres wide. How tall is it?

asked Dec 31, 2015 by pady_1

0 answers

Simplify $\large\frac{9}{10} \div (\large\frac{3}{5} + 2\large\frac{1}{10})$

asked Dec 31, 2015 by pady_1

0 answers

Debbie bought 9 jumpers at the mall. Each jumper cost ₹916. How much money did Debbie spend?

asked Dec 31, 2015 by pady_1

0 answers

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