WBJEE Physics Test - 10 - JEE MCQ

A steel wire is 1m long and 1mm² in area of cross-section. If it takes 200N to stretch this wire by 1mm, how force will be required to strech the wire of the same material and diameter from its normal length of 10m to length of 1002cm

A body revolved around the sun 27 times faster then the earth what is the ratio of their radii

Transformers are used in

Three capacitors of capacitances 2 μF, 4 μF and 6 μF are connected in a parallel combination. Their equivalent capacitance will be

Electric charges 1μC , − 1μC and 2 μC are placed in air at the corners A,B and C respectively of an equilateral triangle ABC having length of each side 10 cm. The resultant force on the charge at C is

A mass of M kg is suspended by a weightless string. The horizontal force that is required to displace it until the string makes an angle of 45º with the initial vertical direction is

A long solenoid of length L has a mean diameter D. It has n layers of winding of N turns each. If it carries a current I, the magnetic field at its centre will be

The net charge on a current carrying conductor is

The magnetic susceptibility does not depend upon the temperature in

The force of cohesion is maximum in

A body starts from rest and has an acceleration 20 cm s⁻². What is the distance covered by the body in first 8 seconds?

Consider the following statements
Assertion (A) : On a rainy day, it is difficult to drive a car or bus at high speed
Reason (R) : The value of coefficient of friction is lowered due to wetting of the surface
Of these statements

Galileo's experiment showed that if two bodies of unequal masses are dropped from the same height, the time required by them to reach the ground are equal. But if they are thrown vertically upwards with the same initial velocity, the ratio of the time required to reach the ground is equal to

A simple harmonic motion is represented by :y = 10 sin (20 t + 0.5). The amplitude of this motion is

A radio active nucleus with mass number 'A' splits into the nuclei whose mass numbers are in the ratio 3:2, the ratio of their radii is

A rectangular block of mass m and area of cross-section A floats in a liquid of density ρ. If it is given a small vertical displacement from equilibrium it undergoes oscillation with a time period T. Then

With respect to air, critical angle in a medium for light of red colour [λ₁] is θ. Other facts remaining same, critical angle for light of yellow colour [λ₂] will be

When a man stands a turn-table stretching with two equal loads in hand and rotates. Then he folds his arm. Which of the following statement is correct

A dics of radius 1 m is rotating with an angular velocity of 10 rad-s⁻¹. The linear velocity of the dics on a point 0.5 m from its centre is

The band gap in germanium and silicon in eV respectively is

The most commonly used material for making transistor is

Heat given to a body which rises its temperature by 1�C is

A 10 kg mass falls through 25 m on to the ground and bounces to a height of 0.50 m. Assume that all potential energy lost is used in heating up the mass. The temperature rise will be (Given specific heat of the material is 252 Joule/kg K)

The dimensions of calorie are

If a,b,c are position vectors of vertices ABC, then the position vector of a centroid of ∆ABC is

In a biprism expt., by using light of wavelength 5000 Å, 5 mm wide fringes are obtained on a screen 1.0 m away from coherent sources. The separation between two coherent sources is

A child is sitting on a swing. Its minimum and maximum heights from the ground are 0.75 m and 2m respectively, its maximum speed will be