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Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform mag. field and describe circular path of radius r₁ and r₂ respectively. The ratio of mass of X to that of Y is ___________ (1) √(r₁/r₂) (2) (r₂/r₁) (3) (r₁/r₂)² (4) (r₁/₂2)

Answer: (3) (r1/r2)2 Magnetic Force = q × V × B Centripetal force = mV2/r mV2/r = q × V × B r = (mV/qB) mV =... View Article

Power supplied to a particle of mass 2 kg varies with time as P = 3t²/2 watt, where t is in second. If the velocity of particle at t = 0 is v = 0, the velocity of particle at time t = 2 s will be (1) 2√2 m/s (2) 4 m/s (3) 1 m/s (4) 2 m/s

Answer: (4) 2 m/s According to work-energy theorem, the net work done on a body is equal to change in kinetic energy of the body. It can be... View Article

The S.I unit of permittivity of free space (ϵ0) is (1) CN⁻¹−m⁻¹ (2) Nm^-2C^-2 (3) C²N⁻¹m⁻² (4) C²N⁻¹m^-2

Answer: (4) C2N-1m-2 Permitivity (ε) is the property of every material, which measures the opposition offered against the formation of... View Article

A particle executes a simple harmonic motion of time period T. Find the time taken by the particle to go directly from its mean position to half the amplitude. (1) T/2 (2) T/4 (3) T/8 (4) T/12

Answer: (4) T/12 Simple Harmonic Motion (SHM) is defined as a motion in which the restoring force is directly proportional to the displacement... View Article

How do you convert binary to decimal number?

Answer: A binary number system is defined as a number that is used in binary systems. It is also called base 2 numeral system. It represents the... View Article

Zone refining process is used for the (1) Concentration of an ore (2) Reduction of a metal oxide (3) Purification of metal (4) Purification of an ore

Answer: (3) Purification of metal Zone Refining is a method used for purifying crystals and impurities in the metal to obtain metals with very... View Article

How to calculate percentage? Give example.

Answer: In mathematics, a percentage is a number or ratio that can be expressed as a fraction of 100. If we have to calculate per cent of a... View Article

If a,b,c,d are four positive real numbers such that abcd = 1, then the minimum value of (1 + a)(1 + b)(1 + c)(1 + d) is equal to_________?

Answer: 16 Real numbers are numbers that include both rational and irrational numbers. Rational numbers such as integers (-2, 0, 1),... View Article

A student wants to project the image of a candle flame on the walls of school laboratory by using a lens (1) Which type of lens should be use? (2) At what distance in terms of focal length F of the lens should be place the candle flame so as to get (a) a magnified, and (b) a diminished imaged respectively on the wall?

Answer: (1) The student should use a convex lens since it will allow him to project an image on the walls because the convex lens will create a... View Article

Following cards are put facing down: A E I O U What is the chance of drawing out (1) A card marked U? (2) A vowel (3) A or I (4) A consonant?

Answer: Probability is a measure of the likelihood of an event to occur. Many events cannot be predicted with total certainty. We can predict... View Article

The height of a cone is 15 cm and its volume is 1570 cm3. Find the radius of the base. (Use π = 3.14)

Answer: A cone is a shape formed by using a set of line segments or the lines which connects a common point, called the apex or vertex, to all... View Article

If force F, work W and velocity v are taken as fundamental quantities. What is the dimensional formula of time?

Answer: Velocity is defined as the rate of change of the object’s position with respect to a frame of reference and time. Work is... View Article

If force F, time t and velocity V are taken as fundamental quantities and K is the dimensionless constant of proportionality. What is the dimensional formula for mass?

Answer: Velocity is defined as the rate of change of the object’s position with respect to a frame of reference and time. Work is... View Article

The difference between a 2-digit number and the number obtained by interchanging the digits is 36. What is the difference between the sum and the difference of the digits of the number if the ratio between the digits of the number is 1:2 ? (1) 4 (2) 8 (3) 16 (4) None of these

The difference between a 2-digit number and the number obtained by interchanging the digits is 36. What is the difference between the sum and the... View Article

The position of a body moving along x-axis at time t is given by x = (t²– 4t + 6)m. The distance travelled by body in time interval t = 0 to t = 3s is (1) 5m (2) 7m (3) 4m (4) 3m

Answer: (1) 5m x = t2 - 4t + 6The change in velocity is expressed as .The velocity is changing At t = 0, x1= 6 At t = 2, x2 = 2 Magnitude... View Article

A jet airplane travelling at the speed of 500 kmh^-1 ejects its products of combustion at the speed of 1500 kmh^-1 relative to the jet plane. What is the speed of the latter with respect to an observer on ground? (1) 500 km h^-1 (2) -1000 km h−1 (3) 1500 kmh^-1 (4) 2000 kmh^-1

Answer: - 1000kmh-1 Relative velocity is defined as the velocity of an object B in the rest frame of another object A. The difference between... View Article

A particle of mass m is moving in a circular path of constant radius r such that centripetal acceleration is varying with time t as k²rt², where k is a constant. The power delivered to the particle by the force acting on it is (1) m²k²r²t² (2) mk²r²t (3) mk²rt² (4) mkr²t

Answer: Centripetal acceleration is defined as the property of the motion of an object, traversing a circular path. Any object that is moving in... View Article

The distance x covered by a particle in one-dimensional motion varies with time t as x² = at² + 2bt + c. The acceleration of the particle varies as (1) x−3 (2) x^3/2 (3) x² (4) x^-2/3

Answer: x-3 Let v be velocity,α be the acceleration then, x2 = at2 + 2bt + c 2xv = 2at + 2b xv = at + b_____________(1) v = (at + b)/x... View Article

A pump motor is used to deliver water at a certain rate from a given pipe. To obtain thrice as much water from the same pipe at the same time, the power of the motor has to be increased to (1) 2 times (2) 9 times (3) 27 times (4) 81 times

Answer:(3) 27 times Power is defined as the rate of doing work, it is the work done in unit time. The SI unit of power is Watt (W) which is... View Article

A charge particle (charge q) is moving in a circle of radius R with uniform speed. v The associated magnetic moment m is given by_______

Answer: A charge particle (charge q) is moving in a circle of radius R with uniform speed. v The associated magnetic moment m is given by qvR/2.... View Article

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