WBJEE Physics Test - 5 - JEE MCQ

Which of the following relations is true ?

In an induction coil with resistance, the induced emf will be maximum, when

If the force on a rocket moving with a velocity of 300 m/s is 210 N, then the rate of combustion of fuel is

The electrical conductivity of the earth's atmosphere increases with altitude due to

Two satellites of earth, S₁ and S₂ moving in the same orbit. The mass of S₁ is four times the mass of S₂. Which one of the following statements is true?

Two small balls having equal positive charge q coulomb are suspended by two insulating string of equal length l metre from a hook fixed to a stand. The whole set up is taken in a satellite into space where there is no gravity. The tension in each string is

Two ions having equal masses but charges in the ratio 1:2 are projected perpendicular to a uniform magnetic field with speeds in the ratio 2:3. The ratio of the radii of the circular paths along which the two ions move is

An α -particle of mass 6.4 x 10⁻²⁷ kg and charge 3.2 x 10⁻¹⁹C is situated in a uniform electric field of 1.6 x 10⁵V m⁻¹ . The velocity of the particle at the end of 2 x 10⁻² m path when it starts from rest is

When 2 A current is passed through the coil of a tangent galvanometer, it gives a deflection of 45º. For 60º deflection, the current must be

The horizontal range of a projectile is R, when the angle of projection is 30º. The value of another angle of projection, for the same range, is

A weightless thread can support tension upto 30 N. A stone of mass 0.5 kg is tied to it and is revolved in a circular path of radius 2 m in a vertical plane. If g = 10 m/s², then the maximum angular velocity of the stone will be

At what speed, the velocity head of water is equal to pressure head of 40 cm of Hg ?

The function of the moderator in a nuclear reactor is

A point initially at rest moves along x-axis. Its acceleration varies with time as a = (6t + 5)m/s². If it starts from origin, the distance covered in 2 s is

The length of simple pendulum executing SHM is increased by 21%. The percentage increase in the time period of the pendulum of increased length is

Two simple pendulums of length 0.5 m and 20 m respectively are given small linear displacement in one direction at the same time. They will again be in the phase when the pendulum of shorter length has completed... oscillations

The angle subtended by a coin of radius 1 cm held at a distance of 80 cm from your eyes is

A body is rotating with angular velocity 30 rad/s. If its kinetic energy is 360 J, then its moment of inertia is

A child swinging ona swing in sitting position stands up. The time period of the swing will

In semi-conductor with the increase in temperature its resistance

On increasing the reverse bias to a large value in a P-N junction diode, current

540 g of ice at 0ºC is mixed with 540 g of water at 80ºC. The final temp. of the mixture in ºC will be

Which of the following parameters does not characterise the thermodynamic state of matter?

In C.G.S. system the magnitude of the force is 100 dynes. In another system where the fundamental physical quantities are kilogram, metre and minute, the magnitude of the force is

Vector 2i+aj+k is perpendicular to vector 2i-j-k if a=

The golden view of sea shell is due to

A body of mass m₁ is moving with a velocity V. it collides with another stationary body of mass m₂. They get embedded at the point of collision, the velocity of the system