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Is Magnetic Force Perpendicular To Current

The magnetic force on a current-carrying wire is perpendicular to both the wire and the magnetic field with direction given by the right hand rule.... View Article

What Happens To Voltage When Resistance Decreases

One of the most basic and important laws of electric circuits is Ohm’s law. The law states that the voltage across a conductor is directly... View Article

How Do Electromagnetic Waves Travel In A Vacuum

Electromagnetic waves do not need a medium to propagate, they can pass through vacuum easily which is a near vacuum. Electromagnetic waves spread... View Article

Why Does Magnetic Field Depends On Moving Charges Only

This question can be answered by the basics of special relativity and electrostatics. An objet occupies less space when it is moving than when it... View Article

How Do We Know Light Is An Electromagnetic Wave

Light is a wave made of time-dependent electric and magnetic fields that generate each other, so that the wave propagates. In the 1860s, Scottish... View Article

Do Lasers Produce Coherent Light

Yes, lasers produce coherent light. Coherent light is made of waves all in phase and same wavelengths. The laser light has following properties:... View Article

The Value Of 1 Log 2 Plus Log 2 2 Factorial

(1) log 3 (2) log 2 (3) 1/2 (4) none of these Solution: 1- log 2 + (log 2)2/2! - (log 2)3/3! +... = 1- (log 2)/1! + (log 2)2/2! -... View Article

1 By 2 Factorial Plus 1 By 4 Fact Plus 1 By 6 Fact By 1 Plus 1 By 3 Fact Equals

(1) e+1 (2) (e-1)/(e+1) (3) e-1 (4) none of these Solution: ½! + ¼! + ⅙! +.../1+⅓! + ⅕!+... = Multiply numerator and denominator... View Article

1 By 3 Fact Plus 2 By 5 Is Equal To

(1) e (2) e-1/2 (3) e/4 (4) e/6 Solution: Given ⅓! + ⅖! + 3/7! + …. = 0/1! + ⅓! + ⅖! + 3/7! + …. S = ∑k = 0∞ k / (2k+1)! = (½)... View Article

The Value Of 1 Plus 1 Plus 2 By 2 Factorial Is

(1) e (2) 2e (3) 3e/2 (4) 4e/5 Solution: Given series 1+ 1+2/2! + (1+2+3)/3! + (1+2+3+4)/4! +.... Here tn = (1+2+3+...n)/n! =... View Article

In The Expansion Of E 7x Plus E 3x By E 5x The Constant Term Is

(1) 0 (2) 1 (3) 2 (4) none of these Solution: We use ex = 1+ x/1! + x2/2! + x3/2! +... (e7x + e3x)/e5x = e2x + e-2x = 1+ 2x +... View Article

If A1 A2 An Are In Arithmetic Progression Where A1 Greater Than 0 For All I Then 1 Root A1 Plus Root A2

(1) n2(n+1)/2 (2) (n-1)/(√a1+√an) (3) n(n-1)/2 (4) None of these Solution: Here a1 , a2...an are in AP a1-a2 = a2-a3 = ….=... View Article

Log E 1 Plus 3x By 1 2x Is Equal To

(1) -5x - 5x2/2 - 35x3/3 - … (2) -5x + 5x2/2 - 35x3/3 + … (3) 5x - 5x2/2 + 35x3/3 - … (4) 5x + 5x2/2 + 35x3/3 + … Solution: We... View Article

The Sum Of The Series 3 By 4 8 3 5 By 4 8 12 3 5 7 By 4 Is

(1) √(3/2) - 3/4 (2) √(2/3) - 3/4 (3) √(3/2) - 1/4 (4) √(2/3) - 1/4 Solution: Let S = 3/4. 8 - 3.5/4.8.12 + 3.5.7/4.8.12.16 - ….... View Article

The Sum Of All The Products Of The First N Natural Numbers Taken Two At A Time Is

(1) (1/24)n(n-1)(n+1)(3n+2) (2) (n2/48)(n-1)(n-2) (3) (⅙)n(n+1)(n+2)(n+5) (4) None of these Solution: We know (x1 + x2 + ...xn)2 =... View Article

The Sum Of N Terms Of The Series 1 Plus 1 Plus X Plus 1 Plus X Plus X2 Will Be

(1) (1-xn)/(1-x) (2) x(1-xn)/(1-x) (3) [n(1-x)-x(1-xn)]/(1-x)2 (4) None of the above Solution: Sn = 1 + (1+x) + (1+x+x2) + … n... View Article

The Sum Of N Terms Of The Infinite Series 1 3 2 Plus 2 5 2 Plus 3 7 2 Is

(1) (n/6)(n+1)(6n2+14n+7) (2) (n/6)(n+1)(2n+1)(3n+1) (3) 4n3+4n2+n (4) none of these Solution: Given series 1 . 32 + 2 . 52 + 3 .... View Article

The Sum Of 24 Terms Of The Following Series Root 2 Plus Root 8 Root 18 Is

(1) 300 (2) 200√2 (3) 300√2 (4) 250√2 Solution: Given √2 + √8 + √18 + √32 + ….. 24 terms S = √2 + √8 + √18 + √32 + …. = 1√2 +... View Article

If Sn Eq 1 By 6 11 1 By 11 Upto N Terms Then 6sn Equals

(1) (5n-4)/(5n+6) (2) n/(5n+6) (3) (2n-1)/(5n+6) (4) 1/(5n+6) Solution: 1/6. 11 = (1/5)((1/6) - (1/11)) Let Sn = 1/6.11 + 1/11.16... View Article

Statement 1 The Sum Of Series 1 1 Plus 2 Is 8000

(1) Statement I is incorrect, statement II is correct (2) Statement I is correct; statement II is a correct explanation for statement I... View Article

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