WBJEE Physics Test - 3 - JEE MCQ

When a body is taken from the equator to the poles, its weight

In an ac circuit, with voltage V and current I the power dissipated is

According to Hooke's law force is proportional to

An infinite no. of capacitors with capacitances 1μF, 1/21μF, 1/41μF, 1/81μF, ...etc. are connected in parallel combination. Their equivalent capcitance will be

A capacitor of capacity 10 μ F is charged to 40V and a second capacitor of capacity 15 μ F is charged to 30V. If they are connected in parallel the amount of charge that flows from the smaller capacitor to higher capacitor in μ C is

Rocket engines lift a rocket from earth surface, because hot gases with high velocity

An α-particle and a proton are accelerated at same potential difference from rest. Find the ratio of their final velocity?

A long solenoid carrying a current produces a magnetic field B along its axis. If the current is doubled and the no. of turns per cm is halved, then new value of the magnetic field will be

The magnetic field at a point at a distance 'd' from the centre on axial line of a very short bar magnet of magnetic moment M is B. The magnetic field at a distance '2d' from centre on equitorial line of magnet of magnetic moment 8 M, will be

When the free surface area of a liquid is increased, the surface tension of the liquid

The displacement is given by x=2t²+t+5, the acceleration at t=2s is

A body crosses the topmost point of a vertical circle with critical speed. Its acceleration, when the string is horizontal will be

A body is thrown horizontally from the top of a tower of height 5 m. It touches the ground at a distance of 10 m from the foot of the tower. The initial velocity of the body is (g = 10 ms⁻²)

Among electron, proton, neutron and α - particle the maximum penetration capacity is for

A body is executing S.H.M. when its displacement from the mean position is 4 cm and 5 cm, the corresponding velocity of the body is 10 cm/sec and 8 cm/sec. Then the time period of the body is

A body is executing simple harmonic motion with an angular frequency 2 rad/s. The velocity of the body at 20 mm displacement, when the amplitude of motion is 60 mm, is

The distance travelled by light in glass (refractive index =1.5) in a nanosecond will be

Angular momentum is

The moment of inertia of a thin uniform circular disc about one of the diameters is I. Its moment of inertia about an axis perpendicular to the circular surface and passing through the centre is

The difference in the variation of resistance with temperature in a metal and a semiconductor arises essentially due to the difference in the

P-type semiconductor is formed when
A. As impurity is mixed in Si
B. Al impurity is mixed in Si
C. B impurity is mixed in Ge
D. P impurity is mixed in Ge

Two moles of monoatomic ideal gas at 60ºC are mixed adiabatically with one mole of another monoatomic ideal gas at 12ºC. The final temperature of the mixture is

A heat engine is a device

The dimensional formula for Planck's constant (h) is

If are a right handed triad of mutually perpendicular vectors of magnitude a, b, c, then the value of is

When a star moves away from earth, the spectrum of the star shifts towards higher wavelength side. This is due to

If the kinetic energy of a body changes by 20% then its momentum would change by