Archives

What are azeotropic refrigerants?

A refrigerant is either a pure compound or a mixture of two or more refrigerants. The mixture of more than one refrigerant is called an... View Article

How is the high voltage generated?

Rectifiers are used to convert high voltage alternating current to high voltage direct current. Transformers are used to step up and step down... View Article

When two or more refrigerants are mixed?

When two or more refrigerants are mixed together it forms an azeotropic mixture. Azeotropic refrigerant is a mixture of two or more components... View Article

Why is the transistor not used as a rectifier?

In order to use a transistor as a rectifier, either the emitter-base segment or the collector-base segment must be used. In a transistor, the... View Article

Why are coils made of copper?

Copper has a very low electrical resistance which means that it is easy for the current to flow through the copper coils. The copper wires can be... View Article

Which instrument is based on the induction principle?

The principle of induction is used in the following instruments Current lamp Induction cooking Induction motors Induction charging... View Article

What causes the inductance?

When there is a flow of current in the circuit it causes a change in the magnetic field. The change in the magnetic field causes the inductance.... View Article

Can Capacitors be negative?

The capacitance of the capacitor is the ratio of the amount of electric charge stored on the plates of the capacitor to the voltage. C = Q/V... View Article

cos^-1 (15 / 17) + 2 tan^-1 (1 / 5) =

1) π / 2 2) cos-1 (171 / 221) 3) π / 4 4) None of these Solution: (4) None of these cos-1 (15 / 17) + 2 tan-1 (1 / 5) = cos-1... View Article

2 tan^-1 (1 / 3) + tan^-1 (1 / 7) =

1) tan-1 (49 / 29) 2) π / 2 3) 0 4) π / 4 Solution: (4) π / 4 2 tan-1 (1 / 3) + tan-1 (1 / 7) = tan-1 [2 (1 / 3)] / [1 - (1 /... View Article

If sin^-1 (x / 5) + cosec^-1 (5 / 4) = ? / 2, then x =

1) 4 2) 5 3) 1 4) 3 Solution: (4) 3 sin-1 (x / 5) + cosec-1 (5 / 4) = π / 2 sin-1 (x / 5) = (π / 2) - cosec-1 (5 / 4) sin-1 (x /... View Article

If tan^-1 2x + tan^-1 3x = ? / 4, then x =

1) -1 2) 1 / 6 3) -1, 1 / 6 4) None of these Solution: (2) 1 / 6 tan-1 2x + tan-1 3x = π / 4 tan-1 [2x + 3x] / [1 - (2x) (3x)] =... View Article

tan^-1 [a – b] / [1 + ab] + tan^-1 [b – c] / [1 + bc] =

1) tan-1 a - tan-1 b 2) tan-1 a - tan-1 c 3) tan-1 b - tan-1 c 4) tan-1 c - tan-1 a Solution: (2) tan-1 a - tan-1 c tan-1 [a - b]... View Article

cos [2 cos^-1 (1 / 5) + sin^-1 (1 / 5)] =

1) 2 √6 / 5 2) - 2 √6 / 5 3) 1 / 5 4) - 1 / 5 Solution: (2) - 2 √6 / 5 cos [2 cos-1 (1 / 5) + sin-1 (1 / 5)] = cos [cos-1 (1 / 5)... View Article

The value of sin [2 cos^-1 ?5 / 3] is

1) √5 / 3 2) 2√5 / 3 3) 4 √5 / 9 4) 2 √5 / 9 Solution: (3) 4 √5 / 9 sin [2 cos-1 √5 / 3] = sin [cos-1 {2 (√5 / 3)2 - 1}] = sin... View Article

If tan^-1 x – tan^-1 y = tan^-1 A, then A =

1) x - y 2) x + y 3) [x - y] / [1 + xy] 4) [x + y] / [1 - xy] Solution: (3) [x - y] / [1 + xy] tan-1 x - tan-1 y = tan-1 A tan-1... View Article

Let cos (2 tan^-1 x) = 1 / 2, then the value of x will be

1) √3 2) 1 / √3 3) 1 - √3 4) 1 - (1 / √3) Solution: (2) 1 / √3 cos (2 tan-1 x) = 1 / 2 cos (2 tan-1 x) = cos π / 3 tan-1 x = π /... View Article

If tan^-1 x + tan^-1 y + tan^-1 z = ? / 2, then

1) x + y + z - xyz = 0 2) x + y + z + xyz = 0 3) xy + yz + zx + 1 = 0 4) xy + yz + zx - 1 = 0 Solution: (4) xy + yz + zx - 1 = 0... View Article

cot^-1 (3 / 4) + sin^-1 (5 / 13) =

1) sin-1 63 / 65 2) sin-1 12 / 13 3) sin-1 65 / 68 4) sin-1 5 / 12 Solution: (1) sin-1 63 / 65 Let cot-1 3 / 4 = θ cot θ = 3 / 4... View Article

tan^-1 1 + tan^-1 2 + tan^-1 3 =

1) π / 2 2) π / 3 3) 0 4) None of these Solution: (4) None of these tan-1 1 + tan-1 2 + tan-1 3 = tan-1 1 + π + tan-1 (5 / - 5)... 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