Archives

If a semiconductor photodiode can detect a photon with a maximum wavelength of 400nm

If a semiconductor photodiode can detect a photon with a maximum wavelength of 400nm, then its band gap energy is : Planck’s constant h =... View Article

The mass density of a planet of radius R varies with the distance r

The mass density of a planet of radius R varies with the distance r from its centre as ρ(r) = ρ 0(1-(r2/R2)). Then the gravitational... View Article

A block of mass m attached to a massless spring

A block of mass m attached to a massless spring is performing oscillatory motion of amplitude ‘A’ on a frictionless horizontal plane. If half of... View Article

The speed verses time graph for a particle is shown in the figure.

The speed verses time graph for a particle is shown in the figure. The distance travelled (in m) by the particle during the time interval t = 0... View Article

In a photoelectric effect experiment, the graph of stopping potential V

In a photoelectric effect experiment, the graph of stopping potential V versus reciprocal of wavelength obtained is shown in the figure. As the... View Article

Identify the operation performed by the circuit

Identify the operation performed by the circuit given below: 1) NOT 2) OR 3) AND 4) NAND Answer: (3) Hence option 3 is the answer.... View Article

For a uniform rectangular sheet shown in the figure

For a uniform rectangular sheet shown in the figure, the ratio of moments of inertia about the axes perpendicular to the sheet and passing... View Article

A quantity x is given by (IFv²/WL⁴) in terms of moment of inertia I, force F, velocity v, work W and Length L.

A quantity x is given by (IFv2/WL4) in terms of moment of inertia I, force F, velocity v, work W and Length L. The dimensional formula for x is... View Article

If for all real triplets (a,b,c) and f(x) = a + bx + cx2 then integration of f(x)dx is equal to

a) 2(3f(1)+2f(1/2)) b) (1/3)(f(0)+f(1/2)) c) (1/2) (f(1)+3f(1/2)) d) (1/6)(f(0)+f(1)+4f(1/2)) Solution: f(x) = a+ bx + cx2 f(0) = a, f(1) =... View Article

Negation of the statement: ′√5 is an integer or 5 is irrational′ is

a) √5 is irrational or 5 is an integer.b) √5 is not an integer or 5 is not irrational.c) √5 is an integer and 5 is irrational.d) √5 is not an... View Article

If f’(x) = tan ^-1 (sec x + tan x ), (-π/2) < x < (π/2), and f(0) = 0, then f(1) is equal to:

a) (π+1)/4b) (π+2)/4c) 1/4d) (π-1)/4Solution:f’(x) = tan-1 (sec x + tan x) = tan-1 ((1+ sin x)/cos x ) f’(x) = (π/4) + (x/2)f(x) = (π/4) x+... View Article

Let z be a complex number find the value of |z+3i|

Let z be a complex number such that Answer: (b)... View Article

If the matrices A is given, B = adj A and C = 3A, then …

If the matrices A = = 13 + 1 - 8= 6B = adj(A) ǀadj Bǀ = ǀadj (adj A)ǀ = ǀAǀ4 = 64 ǀCǀ = ǀ3Aǀ = 33ǀAǀ = 33 × 6 = 64/(33×6)= 8Answer: (c)... View Article

If f(x) is continuous at x = 0 then a + 2b is equal to:

If f(x) = is continuous at x = 0 then a + 2b is equal to:a) -2b) 1c) 0d) 1Solution:f(x) is continuous at x = 0 a + 3 = 1 a = -2a + 2b = 0Answer: (c)... View Article

Let z be those complex number which satisfies |z + 5| ≤ 4 and z (1 + i) + [latex]bar{z}[/latex] (1 – i) ≥ – 10, i = √-1. If the maximum value of |z + 1|² is ɑ + β√2, then the value of ɑ + β is

Solution:Answer: 48Given, |z + 5| ≤ 4(x + 5)2 + y2 ≤ 16Also, z (1 + i) + (1 - i) ≥ - 10x - y ≥ - 5 ---- (2)From (1) and... View Article

Let the normals at all the points on a given curve pass through a fixed point (a, b). If the curve passes through (3, – 3) and (4, – 2 √2), and given that a – 2√2b = 3, then (a² + b² + ab) is equal to

Solution:Answer: 9Let the equation of normal is Y - y = (- 1 / m) (X - x), where m = dy / dxAs it passes through (a, b)b - y = (- 1 / m) (a - x)... View Article

If the arithmetic mean and the geometric mean of the p^th and q^th terms of the sequence – 16, 8, – 4, 2, … satisfy the equation 4x² – 9x + 5 = 0, then p + q is equal to

Solution:Answer: 10Given, 4x2 - 9x + 5 = 0(x - 1) (4x - 5) = 0AM = 5 / 4, GM = 1 (AM ≥ GM)Again for the series, - 16, 8, - 4, 2, …pth... View Article

For some real numbers α and β, then β -ɑ is equal to

If the matrix for some real numbers ɑ and β, then β -ɑ is equal to_________.Solution:Answer: 4... View Article

Let L be a common tangent line to the curves 4x² + 9y² = 36 and (2x)² + (2y)² = 31. Then the square of the slope of the line L is

Solution:Answer: 3E : (x2 / 9) + (y2 / 4) = 1C : x2 + y2 = 31 / 4The equation of the tangent to the ellipse is y = mx ± √(9m2 + 4)... View Article

In I_m,n = ∫₀¹ x^m-1

In Im,n = ∫01 xm-1 (1 - x)n-1 dx, for m, n ≥ 1 and ∫01 [xm-1 + xn-1] / [(1 + x)m+n] dx = ɑIm,n, ɑ belongs to R, then ɑ =Solution:Answer: 1... View Article

M	T	W	T	F	S	S
			1	2	3	4
5	6	7	8	9	10	11
12	13	14	15	16	17	18
19	20	21	22	23	24	25
26	27	28	29	30	31