The primary and secondary coils of a transformer have 50 and 1500 turns respectively. If the magnetic flux φ linked with the primary coil is given by φ = φ 0 + 4t, where φ is in weber, t is time in second and φ 0 is a constant, the output voltage across the secondary coil is
Angular displacement θ of a fly wheel varies with time as θ = at + bt2 + ct3, then angular acceleration is given by
Eight dipoles of charges of magnitude are placed inside a cube. The total electric flux coming out of the cube will be
If density of earth increased 4 times and its radius become half of what it is, our weight will
Two long parallel wires carry equal current I in the same direction. The length of each wire is l and the distance between them is a. Force acting on each wire is
The magnetic compass is not useful for navigation near the magnetic poles. Since
A spherical drop of water has 1 mm radius. If the surface tension of water is 70 x 10⁻3 N-m⁻1, then difference of pressures between inside and outside of spherical drop is
A body freely falling from rest has a velocity ν after it falls through a height h. The distance it has to fall down furthur for its velocity to become double, is
A lift of mass 1000 kg is moving with an acceleration of 1 m/s2 in upward direction. Tension developed in the string, which is connected to the lift, is
The mass of the lift is 1000 Kg , the acceleration of 1 m / s^2 and the acceleration due to gravity is 9.8 m / s^2 .
The tensions developed in strings is given as ,
T = mg + ma
===》 1000 × 9.8 + 1000 × 1
=====》 10800 N
Thus , the tensions developed in strings is 10800 N.
A pendulum bob has a speed of 3 m/s at its lowest position. The pendulum is 0.5 m long. The speed of the bob, when the length makes an angle of 60o to the verticle, will be (If g=10 m/s2)
The radius of gyration of a uniform rod of length L about on axis passing through its centre of mass is
Water rises in a capillary tube when its one end is dipped vertically in it, is 3 cm. If the surface tension of water is 75 x 10⁻3 N/m, then the diameter of capillary will be
If a ball of 80 kg mass hits an ice cube and temperature of ball is 100oC, how much ice becomes water? Specific heat of ball is 0.2 cal/gram.
The unit of absolute permittivity is
A constant power P is applied to a car starting from rest. If v is the velocity of the car at time t, then
The force constant of a weightless spring is 16 N/m. A body of mass 1.0 Kg suspended from it is pulled down through 5 cm and then released. The maximum kinetic energy of the system will be