Recent questions tagged mock-test-series-2015

In a plane electromagnetic wave, the electric field oscillates sinusoidally at a frequency of $2.0 x 10^{10}Hz$ and amplitude $48V/m$ 1. What is the wavelength of the wave? 2. What is the amplitude of the oscillating magnetic field? 3. Show that the average energy density of the $E$ field equals the average density of the B field.

asked Feb 10, 2015 by meena.p

0 answers

A $4 \mu F$ capacitor is charged by a $200\;V$ supply. Then, it is disconnected from the supply and is connected to another uncharges $2 \mu F$ capacitor. How much electrostatic energy of the first capacitor is lost in the form of heat and electromagnetic radiation?

asked Feb 10, 2015 by meena.p

0 answers

Two charged conducting spheres of radii a and b are connected to each other by a wire. What is the raio of elecetric field at the surfaces of the two spheres? Use the result obtained to explain why charge density on the sharp and pointed ends of the conductor is higher than at its flatter portions?

asked Feb 10, 2015 by meena.p

0 answers

State Biot Savart law. Use it to obtain the intensity of magnetic field at a point due to a long straight current carrying wire.

asked Feb 10, 2015 by meena.p

0 answers

The angle of dip at a place in Kerala is $18^{\circ}$. Will its value be more or less at a place in Kashmir.? Give reasons?

asked Feb 10, 2015 by meena.p

0 answers

Define the term ‘angle of dip’. Derive the relation between the angle of dip and the resultant magnetic field of earth at a place .

asked Feb 10, 2015 by meena.p

0 answers

A light bulb is rated $100 w$ for $220 \;V \;AC$ supply of $50\; Hz$. Calculate. A) resistance of the bulb B) the rms current of the bulb

asked Feb 10, 2015 by meena.p

0 answers

Use Lenz’s law to determine the direction of induced current in the situations described by the figure. 1. A wire of irregular shape turning into a circular shape 2. A circular loop being deformed into a narrow straight wire.

asked Feb 10, 2015 by meena.p

0 answers

A proton has spin and magnetic moment just like an electron. Why is its effect neglected in magnetism of materials ?

asked Feb 10, 2015 by meena.p

0 answers

The output of a $NAND$ gate is fed to a $NOT$ gat. Write the truth table for the final output of the combination.

asked Feb 10, 2015 by meena.p

0 answers

Define $\alpha$ and $\beta$ of a transistor . How are they related?

asked Feb 10, 2015 by meena.p

0 answers

Two metal plates have a work function of $2eV$ and $5eV$. Which metal will emit electrons, when it is radiated with light of wavelength $400\;nm$ and why?

asked Feb 10, 2015 by meena.p

0 answers

What is meant by data retrieval?

asked Feb 10, 2015 by meena.p

0 answers

What is space communication? What are the modes of communication?

asked Feb 10, 2015 by meena.p

0 answers

Why do we prefer a potentiometer to measure the emf of a cell rather than a voltmeter?

asked Feb 10, 2015 by meena.p

0 answers

Give the logic symbol for NOR gate.

asked Feb 10, 2015 by meena.p

0 answers

An electron does not suffer any deflection while passing through a region of magnetic field. What is the direction of the magnetic field?

asked Feb 10, 2015 by meena.p

0 answers

Evaluate : $\int \large\frac{1- \cos x}{\cos x(1+\cos x)}$$dx$

asked Feb 10, 2015 by meena.p

1 answer

Evaluate : $\int \large\frac{1}{1+ 3 \sin ^2 x +8 \cos ^2 x}$$dx$

asked Feb 10, 2015 by meena.p

1 answer

An amount of $Rs. 5000$ is put into three investments at the rate of interest of $6\%,7\%$ and $8\%$ per annum respectively . The total annual income is $Rs. 385$ If the combined income from the first two investments is $Rs. 70$ more than the income from the third , find the amount of each investment by matrix method.

asked Feb 10, 2015 by meena.p

1 answer

If a machine is correctly setup, it produces $90\%$ acceptable items. If it is incorrectly setup, it produces only $40 \% $ acceptable items . past experience shows that $80\%$ of the setups are correctly done . If after a certain setup, the machine produces 2 acceptable items, find the probability that machine is correctly setup.

asked Feb 10, 2015 by meena.p

0 answers

Let the point $(2,3,4)$ lie on the top of Tajmahal. Find the perpendicular distance of the point $(2,3,4)$ from the line $\large\frac{(4x)}{2}=\frac{y}{6} =\frac{(1-z)}{3}$.Also find the coordinates of the perpendicular. Do you think that heritage is important is important for the country and its people ?

asked Feb 10, 2015 by meena.p

0 answers

If the length of the three sides of a trapezium other than the base are equal to 10 cm , then find the area of the trapezium when it is maximum .

asked Feb 10, 2015 by meena.p

1 answer

Find the area bounded by the curve $y= 2x-x^2$ and the straight line $y=-x$

asked Feb 10, 2015 by meena.p

1 answer

Compute the area bounded by the lines $x+2y =2 ; y-x =1$ and $2x+y=7$

asked Feb 10, 2015 by meena.p

1 answer

A small manufacturer has employed 5 skilled men 10 semi - skilled men and makes an article in two qualities deluxe model and an ordinary model. The making of a deluxe model requires 2 hrs work bt skilled man and 2 hrs work by a semi skilled man. The ordinary model requires 1 hr by a skilled man and 3 hrs by a semi skilled man. By union rules no mam may work more than 8 hrs per day. The manufactures clear profit on deluxe model is Rs.15 and an orsinary model is Rs. 10. How many of each type should be made in order to maximize his total daily profit.

asked Feb 10, 2015 by meena.p

1 answer

Prove that $\large\frac{dy}{dx}=\frac{[\sin ^2(a+y)]}{\sin a}$

asked Feb 10, 2015 by meena.p

0 answers

Find the distance between the planes, $2x-y+2z=-3$ and $-2y+4x+4z+5=0$

asked Feb 10, 2015 by meena.p

0 answers

Find the cartesian equation of the line passing through the points , $A(2,-1,3)$ and $B(4,2,1)$

asked Feb 10, 2015 by meena.p

0 answers

Find the cartesian equation of the line passing through the points , $A(2,-1,3)$ and $B(4,2,1)$

asked Feb 9, 2015 by meena.p

0 answers

Find a unit vector perpendicular to each of the vectors , $\overrightarrow{a}+\overrightarrow{b}$ and $\overrightarrow{a}- \overrightarrow{b}$ where $\overrightarrow{a}= 3 \hat i +2 \hat j+2 \hat k$ and $\overrightarrow{b}= \hat i +2 \hat j- 2\hat k$

asked Feb 9, 2015 by meena.p

0 answers

Find the intervals in which $f(x) = \log (1+x) \large\frac{-x}{(1+x)}$

asked Feb 9, 2015 by meena.p

1 answer

Find the points on the curve $4x^2+9y^2=14$, where the tangents are perpendicular to the line $2y +x =0$

asked Feb 9, 2015 by meena.p

1 answer

Use differentials to find the approximate value of $\sqrt {0.037}$

asked Feb 9, 2015 by meena.p

1 answer

If $x^{my^n}=(x+y)^{m+n}$, prove that $\large\frac{dy}{dx}=\frac{y}{x}$

asked Feb 9, 2015 by meena.p

1 answer

If $x^y =e^{(x-y)}$, prove that $\large\frac{dy}{dx}= \large\frac{\log x}{(1+\log x)^2}$

asked Feb 9, 2015 by meena.p

0 answers

Using the properties of determinants prove the following : $\begin{vmatrix}3a & -a+b & -a+c \\ a-b & 3b & c-b \\ a-c & b-c & 3c \end{vmatrix}$$=3( a+b+c)(ab+bc+ca)$

asked Feb 9, 2015 by meena.p

0 answers

Find the differential equation of the family of curves given by $y^2-2ky +x^2=k^2$

asked Feb 9, 2015 by meena.p

1 answer

Evaluate $\int \limits ^{\pi/4} _{-\pi/4} |\sin x |dx$

asked Feb 9, 2015 by meena.p

0 answers

Solve : $\int \large\frac{2 \sin x + 3 \cos x}{3 \sin x +4 \cos x }$$dx$

asked Feb 9, 2015 by meena.p

1 answer

Solve :$\int \large\frac{\sin \theta \cos \theta}{\cos ^2 \theta - \cos \theta -2}$$d \theta$

asked Feb 9, 2015 by meena.p

0 answers

A water tank has a shape of an inverted right circular cone with its axis vertical and vertex lower most. Its semi vertical angle is $\tan^{-1} (0.5)$.Water is poured into it at a constant rate of 5 cubic meter per hour. Find the rate at which the level of the water is rising at the instant when the depth of water in the tank is $4\; m$

asked Feb 9, 2015 by meena.p

2 answers

Verify Rolle's theorem for the function $f(x)= \sin x + \cos x , x \in [0,\pi/2]$

asked Feb 9, 2015 by meena.p

0 answers

A die is tossed thrice. getting an even number is considered as success . What is the variance of the binomial distribution ?

asked Feb 9, 2015 by meena.p

1 answer

Find the angle between the vectors $ \overrightarrow {a} = \hat i - \hat j$ and $\overrightarrow {b} = \hat j +\hat k$

asked Feb 9, 2015 by meena.p

1 answer

What is the integrating factor of $\large\frac{dy}{dx}$4+y \sec x =\tan x $ ?

asked Feb 9, 2015 by meena.p

1 answer

If the binary operation * on the set of integers Z, is defined by $a * b = a+3b^2$ then find the value of $8 * 3$

asked Feb 9, 2015 by meena.p

1 answer

Solve $2 \tan ^{-1} (\cos x)= \tan ^{-1} (2 cosec \;x)$

asked Feb 9, 2015 by meena.p

1 answer

Prove that $(A^{-1})'=(A')^{-1}$, where A is an invertible matrix .

asked Feb 9, 2015 by meena.p

0 answers

State Guass’s theorem in electrostatics. Use it to obtain field strength ata distance x from an infinitely large flat charged sheet having surface charge density $\sigma$

asked Jan 30, 2015 by meena.p

0 answers

Ask Questions, Get Answers