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Is Negative Delta H Exothermic

Energy is produced in an exothermic reaction when the total energy of the materials is below the total energy of the reactants. The shift in... View Article

Which Ions Will Cause Hardness In Water Sample

The presence of Ca(HCO3)2 and Mg(HCO3)2 bicarbonates of calcium and magnesium induces transient stiffness in water. The presence of soluble... View Article

Why Do We Use Electromagnetic Spectrum

Electromagnetic spectrum, the overall electromagnetic radiation distribution by frequency or wavelength. While all electromagnetic waves... View Article

Why Ph Is From 1 To 14

The general definition of a solution's pH value is the negative base-10 log of the solution's hydronium ion concentration. While there is no more... View Article

What Happens When An Ionic Compound Dissolves

The water molecules must be able to stabilise the ions that result from splitting the ionic bond to dissolve an ionic compound. Through hydrating... View Article

The Value Of Tan 70 Tan 20 Tan 50 Is

1) 2 2) 1 3) 0 4) 3 Answer: (1) 2 Solution: 70° - 20° = 50° Taking “tan” on both sides, tan(70° - 20°) = tan 50° (tan 70° - tan 20°)/ (1... View Article

Cos 9 Sin 9 Cos 9 Sin 9 Is Equal To

1) tan 26° 2) tan 81° 3) tan 51° 4) tan 54° 5) tan 46° Answer: (4) tan 54° Solution: (cos 9° + sin 9°)/ (cos 9° - sin 9°)... View Article

If Alpha Beta Pi 2 And Beta Gamma Alpha Then The Value Of Tan Alpha Is

1) tan β + tan γ 2) 2(tan β + tan γ) 3) tan β + 2 tan γ 4) 2 tan β + tan γ Answer: (3) tan β + 2 tan γ Solution: Given, α + β = π/2 and β... View Article

If P Cos 55 Q Cos 65 And R Cos 175 Then The Value Of 1 P 1 Q R Pq Is

1) 0 2) - 1 3) 1 4) None of these Answer: (1) 0 Solution: Given, p = cos 55° , q = cos 65° and r = cos 175° 1/p + 1/q + r/pq = (q... View Article

Sin 120 Cos 150 Cos 240 Sin 330 Is Equal To

1) 1 2) - 1 3) 2/3 4) -(√3 + 1)/4 Answer: (2) - 1 Solution: sin 120° cos 150° - cos 240° sin 330° = sin(90° + 30°) cos(180° - 30°)... View Article

If Tan Alpha M M 1 And Tan Beta 1 2m 1 Then Alpha Beta Is

1) π/3 2) π/4 3) 0 4) π/2 Answer: (2) π/4 Solution: Given, tan α = m/(m + 1)....(i) tan β = 1/(2m + 1)....(ii) tan(α + β) = (tan... View Article

If Sin X Y Sin X Y A B A B Then Tan X Tan Y Is Equal To

1) a2/b2 2) a/b 3) b/a 4) (a2 + b2)/(a2 - b2) Answer: (2) a/b Solution: Given, sin(x + y)/sin(x - y) = (a + b)/(a - b) Using... View Article

The Value Of Cos 2 Pi 4 Theta Sin 2 Pi 4 Theta Is

1) 0 2) cos 2θ 3) sin 2θ 4) cos θ Answer: (1) 0 Solution: As we know, cos2x - sin2y = cos(x + y) cos(x - y) cos2(π/4 + θ) - sin2(π/4 - θ)... View Article

Tan 80 Degrees Tan 10 Degrees Tan 70 Degrees Is Equal To

1) 0 2) 1 3) 2 4) 3 Answer: (3) 2 Solution: 80° - 10° = 70° Taking “tan” on both sides, tan(80° - 10°) = tan 70° (tan 80° - tan 10°)/(1... View Article

If Tan A 2 Tan B Cot B Then 2 Tan A B Is Equal To

1) tan B 2) 2 tan B 3) cot B 4) 2 cot B Answer: (3) cot B Solution: Given, tan A = 2 tan B + cot B tan A = 2 tan B + (1/tan B)... View Article

If Sin A 1 Root10 And Sin B 1 Root5 Where A And B Are Positive Acute Angles Then A B

1) π 2) π/2 3) π/3 4) π/4 Answer: (4) π/4 Solution: Given, sin A = 1/√10 and sin B = 1/√5 We know that sin2x + cos2x = 1 Thus,... View Article

If Sin A Cos B A And Sin B Cos A B Then Sin A B Is

1) (a2 + b2)/2 2) (a2 - b2 + 2)/2 3) (a2 + b2 - 2)/2 4) None of these Answer: (3) (a2 + b2 - 2)/2 Solution: Given, sin A + cos B =... View Article

If Alpha Beta Gamma 2theta Then Cos Theta Cos Theta Alpha

1) 4 sin(α/2) cos(β/2) sin(γ/2) 2) 4 cos(α/2) cos(β/2) cos(γ/2) 3) 4 sin(α/2) sin(β/2) sin(γ/2) 4) 4 sin α sin β sin γ Answer: (2) 4... View Article

If A 35 B 15 And C 40 Then Tan A Tan B Tan B Tan C Tan C Tan A Is

1) 0 2) 1 3) 2 4) 3 Answer: (2) 1 Solution: Given, A = 35°, B = 15°, C = 40° A + B + C = 35° + 15° + 40° = 90° Taking “tan” on both... View Article

The Value Of Cos Pi 15 Cos 2pi 15 Cos 4pi 15 Cos 8pi 15 Is

1) 1/16 2) -(1/16) 3) 1 4) 0 Answer: (2) -(1/16) Solution: cos(π/15) cos(2π/15) cos(4π/15) cos(8π/15) [cos(4π/15) cos(π/15)]... View Article