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If The Sum Of The 10 Terms Of An Ap Is 4 Times To The Sum Of Its 5 Terms Then The Ratio Of First Term And Common Difference Is

(1) 1 : 2 (2) 2 : 1 (3) 2 : 3 (4) 3 : 2 Solution: Sn= (n/2)(2a+(n-1)d) Given S10 = 4S5 (10/2)(2a+(10-1)d) = 4(5/2)(2a+(5-1)d)... View Article

There Are 15 Terms In An Arithmetic Progression Its First Term Is 5 And Their Sum Is 390 The Middle Term Is

(1) 23 (2) 26 (3) 29 (4) 32 Solution: Given n = 15 a = 5 Sum, Sn = 390 (n/2)(2a+(n-1)d) = 390 (15/2)(2×5+(15-1)d) = 390... View Article

The Number Of Terms Of The Ap 3 7 11 15 To Be Taken So That The Sum Is 406 Is

(1) 5 (2) 10 (3) 12 (4) 14 Solution: Given AP is 3,7,11,15.. Here a = 3 d = 7-3 = 4 Sum, Sn = (n/2)(2a+(n-1)d) 406 =... View Article

If Sum Of N Terms Of An Ap Is 3n2 Plus 5n And Tm Equal 164 Then M Is Equal To

(1) 26 (2) 27 (3) 28 (4) None of these Solution: Given Sn = 3n2 + 5n S1 = 3 + 5 = 8 a = 8 S2 = 3×22 + 5×2 = 12+10 = 22 Second term =... View Article

7th Term Of An Ap Is 40 Then The Sum Of First 13 Terms Is

(1) 53 (2) 520 (3) 1040 (4) 2080 Solution: Given a7 = 40 a+6d = 40 Sum of first 13 terms = a+ a+d + a+2d +.... +a+12d =... View Article

The Sum Of Numbers From 250 To 1000 Which Are Divisible By 3 Is

The sum of numbers from 250 to 1000 which are divisible by 3 is (1) 135657 (2) 136557 (3) 161575 (4) 156375 Solution: Sum = 252 +... View Article

If The Sum Of The First 2n Terms Of Ap 2 5 8 Is Equal To The Sum Of The First N Terms Of Ap 57 59 61 Then N Is Equal To

If the sum of the first 2n terms of A.P 2,5,8,... is equal to the sum of the first n terms of A.P 57,59,61,...., then n is equal to (1) 10... View Article

The Sum Of The First And Third Term Of An Arithmetic Progression Is 12 And The Product Of First And Second Term Is 24 Then First Term Is

(1) 1 (2) 8 (3) 4 (4) 6 Solution: Let a-d, a , a+d be the 3 terms of AP. a-d+a+d = 12 2a = 12 a = 6 (a-d)a = 24 (6-d)= 24/6... View Article

The Sum Of The Integers From 1 To 100 Which Are Not Divisible By 3 Or 5 Is

(1) 2489 (2) 4735 (3) 2317 (4) 2632 Solution: Sum of integers which are not divisible by 3 or 5 = sum of first 100 natural numbers... View Article

What Is H In Magnetic Field

H is the magnetic field produced by the flow of current through the wire. The expression for H can be written as H = (B/µ) - M. B is the... View Article

Why Is Silicon A Semiconductor

An atom of silicon has 14 electrons around the nucleus. Out of these 14, four are valence electrons. The atoms of the best semiconductors have... View Article

Is Aluminium A Semiconductor

Aluminium nitride, aluminium phosphide, aluminium phosphide, aluminium antimonide and aluminium arsenide are examples of semiconductor materials.... View Article

What Materials Can Block Radiation

Lead is a well-suited material for blocking x-rays and gamma rays. Lead has a high atomic number that makes it suitable for blocking radiation.... View Article

Is Lead A Semiconductor

Lead sulfide is also known as galena is an important compound of lead. It was one of the earliest materials used as semiconductors as it... View Article

Which Rays Will Deflect In Electric Field

The alpha rays and beta rays get deflected by the electric field. Alpha rays are positively charged and beta rays are negatively charged. The... View Article

Is Diamond An Insulator

Diamond is a thermal conductor and an electrical insulator. They have a large bandgap and do not have any free electrons for conducting electricity.... View Article

What Would Happen If A Transformer Is Connected To A Dc Supply

When a DC voltage is connected to the primary of the transformer, the constant current produces a constant flux. The EMF induced will be zero in... View Article

Which Two Types Of Motion Are Observed While Rolling A Ball

The two types of motion of the rolling ball are translational motion and rotational motion. The centre of mass of the ball undergoes... View Article

What Is The Relationship Between Mass And Acceleration When Force Is Constant

According to Newton's second law of motion, acceleration is inversely proportional to the mass when the force is a constant. The acceleration is... View Article

What Is The Major Difference Between Static Electricity And Current Electricity

The major difference between static electricity and current electricity is that in static electricity the charges are at rest and get accumulated... View Article