The region between two concentric spheres of radii ‘a’ and ‘b’, respectively (see figure), has volume charge density A r , where A is a constant and r is the distance from the centre. At the centre of the spheres is a point charge Q. The value of A such that the electric field in the region between the spheres will be constant, is :

The Boolean Expression (p   q)  q  ( p  q) is equivalent to :

A man is walking towards a vertical pillar in a straight path, at a uniform speed. At a certain point A on the path, he…

Let two fair sixfaced dice A and B be thrown simultaneously. If E1 is the event that die A shows up four, E 2 is the e…

If the standard deviation of the numbers 2, 3, a and 11 is 3.5, then which of the following is true?

Let a, b and c be three unit vectors such that    3a b c b c . 2    If b is not parallel to c , then the angle…

If the line, x 3 y 2 z 4 2 1 3  lies in the plane, x + my  z = 9, then 2 + m2 is equal to :

The distance of the point (1, 5, 9) from the plane x  y + z = 5 measured along the line x = y = z is :

The eccentricity of the hyperbola whose length of the latus rectum is equal to 8 and the length of its conjugate axis i…

The centres of those circles which touch the circle, x 2 + y2  8x  8y  4 = 0, externally and also touch the x-axis,…

Two sides of a rhombus are along the lines, x  y + 1 = 0 and 7x  y  5 = 0. If its diagonals intersect at (1, 2), t…