Recent questions tagged class12

question no. 25 of exercise 6.5

asked Jan 9, 2014 by guptaaakanksha2_1

1 answer

question no. 25 of exercise 6.5

asked Jan 9, 2014 by guptaaakanksha2_1

0 answers

question no. 25 of exercise 6.5

asked Jan 9, 2014 by guptaaakanksha2_1

0 answers

If a point charge is placed at the centre of closed cylindrical conductor of length l and radius R. the flux through the cylinder will be :

asked Jan 9, 2014 by meena.p

1 answer

A is targetting to B, b and C are targetting to A. probability of hitting the target by A,B and C are $ \large\frac{2}{3}, \large\frac{1}{2} \: and \: \large\frac{1}{3}$ respectively. If A is hit then the probability that B hits the target and C does not is

asked Jan 9, 2014 by thanvigandhi_1

1 answer

A circular ring of radius R has charge Q distributed uniformly on it. If a space of radius R, has its centre lying on boundary of the ring, then flux coming out of sphere will be :

asked Jan 9, 2014 by meena.p

1 answer

Ordinary dice are rolled. The probability that at least half of them will show at least 3 is

asked Jan 9, 2014 by thanvigandhi_1

1 answer

A fair coin is tossed 100 times. The probability of getting tails on odd number of times is

asked Jan 9, 2014 by thanvigandhi_1

1 answer

A coin is tossed 7 times. The probability that he wins the toss on more occasions is

asked Jan 9, 2014 by thanvigandhi_1

1 answer

An infinite long semicircular tube is given as shown below one half is given a surface charge density $+\sigma$ and other half is given charge density $-,\sigma $ . Electric field at a point on axis would be

asked Jan 9, 2014 by meena.p

1 answer

In a binomial distribution $B \bigg( n, P = \large\frac{1}{4} \bigg)$ If the probability of at least one success is greater than or equal to $ \large\frac{9}{10}$ then $n$ is greater than

asked Jan 9, 2014 by thanvigandhi_1

1 answer

If X is binomial variate with parameters $n$ and $p$ where $ 0 < P < 1$ such that $ \large\frac{P(x=r)}{P(x=n-r)}$ is independent of n and r then p equals.

asked Jan 9, 2014 by thanvigandhi_1

1 answer

Mark the correct statements :

asked Jan 9, 2014 by meena.p

1 answer

The correct statement for the phenomenon of "Electrostatic Induction " is :

asked Jan 9, 2014 by meena.p

1 answer

A metal sphere of radius $r_1$ is charged to potential $V_1$ and enclosed in thin spherical shell. If metal sphere is connected to shell by a conductor the potential of shell will be :

asked Jan 8, 2014 by meena.p

1 answer

Equation of the line through the point $(2,-1,-1)$, which is parallel to the plane $4x+y+z+2=0$ ans is $\perp$ to the line $x=\large\frac{y}{-2}=$$z-5$ is ?

asked Jan 8, 2014 by rvidyagovindarajan_1

1 answer

Capacitors $C1$ and $C2$ are joined as shown below. If potential at point A i $V_A$ and point B is $V_B$, Potential at point C is

asked Jan 8, 2014 by meena.p

1 answer

The equation of projection of the line $\large\frac{x-1}{2}=\frac{y-2}{1}=\frac{z-3}{3}$ on the plane $x+y+z=1$ is given by ?

asked Jan 8, 2014 by rvidyagovindarajan_1

1 answer

If the integers m and n are chosen at random between 1 and 100, then the probability that a number of the form $ 7^m+7^n$ is divisible by 5 equals.

asked Jan 8, 2014 by thanvigandhi_1

1 answer

The direction cosine of a line which is $\perp$ to two perpendicular lines whose direction cosines are $(l_1,m_1,n_1)\:\:and\:\:(l_2,m_2,n_2)$ is ?

asked Jan 8, 2014 by rvidyagovindarajan_1

1 answer

The capacitance of capacitors of plate area $A_2 and A_1 (A_2 < A_1) $ at a distance l is

asked Jan 8, 2014 by meena.p

1 answer

The mean and variance of a binomial variate X are 2 and 1 respectively. The probability that X takes a value greater than 1 is

asked Jan 8, 2014 by thanvigandhi_1

1 answer

A and B are two independent events. The probability that both A and B occur is $ \large\frac{1}{6}$ and the probability that neither of them occurs is $ \large\frac{1}{3}$. Then the probability of the two events are respectively

asked Jan 8, 2014 by thanvigandhi_1

1 answer

A pair of dice is rolled together till a sum of either 5 or 7 is obtained. The probability that 5 comes before 7 is

asked Jan 8, 2014 by thanvigandhi_1

1 answer

If electric field $\overrightarrow {E} =( y \hat i + x \hat j ),$ the potential field is

asked Jan 8, 2014 by meena.p

1 answer

Seven white balls and three black balls are randomly placed in a row. The probability that no two black balls are placed adjacently equals

asked Jan 8, 2014 by thanvigandhi_1

2 answers

Capacitance of capacitor becomes $\large\frac{4}{3}$ times its original value if a dielectric slab of thickness $\large\frac{d}{2}$ is inserted b/w the plates (d= seperation between the plates) . The dielectric constant of the slab is:

asked Jan 8, 2014 by meena.p

1 answer

A box contains 24 identical bals of which 12 are white and remaining black. The balls are drawn at random from the box one at a time with replacement. The probability that a white ball is drawn for the 4th time on the 7th draw is

asked Jan 8, 2014 by thanvigandhi_1

1 answer

If two conducting spheres are seperately charged and then brought in contact

asked Jan 8, 2014 by meena.p

1 answer

Charge Q is given displacement $ \overrightarrow {r} = a\hat i + b \hat j $ in electric field $\overrightarrow {E}= E_1 \hat i +E_2 \hat j . $ work done is :

asked Jan 8, 2014 by meena.p

1 answer

The electric potential V at any point (x,y,z) in space is given by $V= gx^2\; volt$. Electric field at $ (2,0,5) m $ in $Vm^{-1}$ is :

asked Jan 8, 2014 by meena.p

1 answer

In one gram solid, there are $10^{22}$ atoms. If one electron is removed from each one of $0.01 \%$ of atoms the charge gained by solid would be :

asked Jan 8, 2014 by meena.p

1 answer

What is effective capacitance between A and B

asked Jan 8, 2014 by meena.p

1 answer

A conductor having a cavity is given a positive charge. What are field strengths $E_A,E_B$ and $E_C$ at point A (inside the cavity), B (with in conductor but outside cavity ) and C (outside the conductor ) respectively ?

asked Jan 8, 2014 by meena.p

1 answer

Choose the correct option : If the point charge is located inside a spherical gaussian surface away from its centre.

asked Jan 8, 2014 by meena.p

1 answer

A charge q is placed at centre of cube of side l. The electric flux through one face of cube will be :

asked Jan 8, 2014 by meena.p

1 answer

125 drops of water of same radius and same charge combine to form a big drop. Ration of potential of big drop to the potential of small drop.

asked Jan 8, 2014 by meena.p

1 answer

In that below diagram $C_1= 4 \mu F, C_2 =12 \mu F, C_3=8 \mu F$ Energy consumed in charging these capacitors is :

asked Jan 8, 2014 by meena.p

1 answer

A charge Q and another charge q are placed at two points A and B which are distance l apart. Keeping q stationary at B, Q is moved to point C such that ABC forms equilateral triangle of side l. Find the net work done ?

asked Jan 8, 2014 by meena.p

1 answer

A hollow conducting sphere of radius R has a charge $+Q$ as its outer surface. Inside the sphere at $r= \large\frac{R}{4}$ from its centre the value of electric potential will be :

asked Jan 8, 2014 by meena.p

1 answer

Three charges Q, +q ans +q are placed at vertices of equilateral triangle. If total electric potential energy of system is zero, the value of Q will be :

asked Jan 8, 2014 by meena.p

1 answer

Charges +q and -q are placed on vertices B and C of isosceles triangle. The potential at vertex A is :

asked Jan 8, 2014 by meena.p

1 answer