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If cabin is decending vertically with acceleration a and action by mass M on floor of cabin is 9Mg/10 then a equals to:

a) g b) g/10 c) (9/10) g d) (10/9) g Answer: b) g/10 Solution: Given. R = 9Mg/10 The cabin is descending vertically then the reaction... View Article

The pull P is just sufficient to keep the block of weight 14 N in equilibrium as shown. Pulleys are ideal. Find the value of P

a) 4 N b) 6 N c) 8 N d) 2 N Answer: d) 2 N Solution: Now if we consider the above figure T1,T2,T3,T4 are the tensions respectively. Now if... View Article

An α-particle moves in a circular path of radius 0.83 cm in the presence of a magnetic field of 0.25 Wb/m2. The de Broglie wavelength associated with the particle will be

(a) 1 Å (b) 0.1 Å (c) 10 Å (d) 0.01 Å Answer: (d) 0.01 Å Solution: Radius of the circular path of a charged particle in a magnetic field is... View Article

A beam of cathode rays is subjected to crossed electric (E) and magnetic fields (B). The fields are adjusted such that the beam is not deflected. The specific charge of the cathode rays is given by :

a) B2/2vE2 b) 2vB2/E2 c) 2vE2/B2 d) E2/2vB2 Answer: d) E2/2vB2 Solution: If the electron beam is not reflected Fm = Ee Bev = Ee v =... View Article

A 25 cm long solenoid has radius 2 cm and 500 total number of turns. It carries a current of 15 A. If it is equivalent to magnet of the same size and magnetization [latex]vec{M}[/latex] Magnetic moment / vloume), then [latex]left|vec{M}right|[/latex] is.

a) 300 A/m b) 30000 A/m c) 30000π A/m d) 3π A/m Answer: b) 30000 A/m Solution: Magnetic moment of solenoid is given as NiA here... View Article

An energy source will supply a constant current into the load if its internal resistance is?

a) equal to the resistance of the load b) very large as compared to the load resistance c) zero d) Non-zero but less than the resistance of... View Article

A charged particle projected in a magnetic field [latex]B = (3hat{i}+4hat{j})times 10^{-2}T[/latex] .The acceleration of the particle is found to be [latex]a = (xhat{i}+2hat{j})m/s^{2}[/latex]. Find the value of x.

Answer: -8/3 m/s2 Solution: (3x + 8) x 10-2 =0 x = -(8/3) m/s2... View Article

A wave y = a sin (wt-kx) on a string meets with another wave producing a node at x = 0. The equation of the unknown wave is

a) y = a sin (wt+ kx) b) y = a cos (kx - wt) c) y = -a cos (kx - wt) d) y = -a sin (kx + wt) Answer: d) y = -a sin (kx... View Article

A moving coil galvanometer A has 200 turns and resistance 100 . Another meter B has 100 turns and resistance 40 . All the other quantities are same in both the cases. The current sensistivity of

a) B is double as that of A b) A is 2.5 times of B c) A is 5 times of B d) B is 5 times of A Answer: a) B is double as that of A Solution:... View Article

A switch S is closed in the circuit shown in figure, current passed through point A is?

a) 4.5 A b)6.0 A c)3.0 A d) Zero Answer: a) 4.5 A Solution: We know by Kirchoff's law that the current at the junction (2V - 40) + (V... View Article

On dividing 2272 as well as 875 by a 3-digit number N, we get the same remainder in each case. The sum of the digits of N is

(a) 10 (b) 11 (c) 12 (d) 13 Solution: Let the three digit number be N and the remainder be r. Let 2272= Nm+r, m∈Z 875 = Nn+r,... View Article

On dividing 624 and 2121 by a 3 digit number we get the same remainder. Find that number?

Solution: Let the three digit number be N and the remainder be r. Let 2121 = Nm+r, m∈Z 624 = Nn+r, n∈Z 2121-624 = N(m-n)... View Article

The average age of a husband and his wife was 23 years at the time of their marriage. After five years, they have a one-year-old child. The average age of the family now is

(a) 19 (b) 23 (c) 29 (d) 28 Solution: Let x be the age of husband and y be the age of wife. Given that the average age = 23 (x+y)/2 = 23... View Article

The probability that a person will hit a target in shooting practice is 0.3. If he shoots 10 times, then the probability of his shooting the target is

(a) 1 (b) 1 - (0.7)10 (c) (0.7)10 (d) (0.3) 10 Solution: The probability that a person will hit a target = 0.3 The probability that a... View Article

The perimeter of a right-angled triangle is 30 cm. If the hypotenuse is 13cm, find its area using Heron’s formula.

Solution: Given perimeter of right-angled triangle is 30 cm. Hypotenuse = 13 cm Let base be b and altitude be a. a2+b2 = 132 ..(i) Also... View Article

A boy is cycling such that the wheels of the cycle are making 140 revolutions per minute. If the diameter of the wheel is 60cm, calculate the speed per hour with which the boy is cycling.

Solution: Given the diameter of wheel = 60 cm Radius of wheel = 60/2 = 30 cm Circumference of wheel = 2πr = 60π = 1320/7 cm Distance... View Article

A running track of 440 ft. is to be laid out enclosing a football field, the shape of which is a rectangle with a semi-circle at each end. If the area of the rectangular portion is to be maximum find the length of its longest sides.

(a) 55 (b) 110 (c) 220 (d) 140 Solution: Let x be the length of the rectangle and y be the breadth of the rectangle. The perimeter of... View Article

The compound interest on Rs 4000 at 10% per annum for 2 years 3 months compounded annually is

(a) Rs. 916 (b) Rs. 900 (c) Rs. 961 (d) Rs. 896 Solution: Given Principal, P = Rs.4000 Rate of Interest, r = 10% Time = 2 years and 3... View Article

The system of equations x+y+z = 6, x+2y+3z = 10, x+2y+λz = μ has no solution if

(a) λ= 3,μ = 10 (b) λ ≠ 3,μ = 10 (c) λ ≠ 3,μ ≠ 10 (d) λ = 3,μ ≠ 10 Solution: x+y+z = 6... View Article

If A and B be two sets such that n(A) = 15, n(B) = 25, then the number of possible values of n(AΔB)(symmetric difference of A and B) is

(a) 30 (b) 16 (c) 26 (d) 40 Solution: Given n(A) = 15 n(B) = 25 n(AΔB) = n(A∪B) - n(A∩B) n(A∪B) = n(A)+n(B) -... View Article