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The minimum and maximum distances of a satellite from the centre of the Earth are 2R and 4R respectively, where R is the radius of Earth and M is the Earth. The radius of curvature at the point of minimum distance is

Using angular momentum conservation, which implies that any of the individual angular momenta can vary as long as the aggregate remains constant.... View Article

A charged particle of mass m and charge q is released from rest in an electric field of constant magnitude E. The kinetic energy of the particle after time t is

Newton’s all three laws of motion are very important for the questions in which objects falling from a particular height for a particular time... View Article

The ratio of escape velocity at earth ve to the escape velocity at a planet vp whose radius and mean density are twice as that of earth is:

Escape velocity is an initial velocity at which, a body when thrown will leave the gravitational field of earth and never come back and its... View Article

In a current carrying load solenoid, the magnetic field produced does not depend upon

A solenoid is a common term for a wire coil used as an electromagnet. It also applies to any system that uses a solenoid to transform electric... View Article

A uniform sphere of mass 500 g rolls without slipping on a plane surface so that its centre moves at a speed of 0.02 m/s . The total kinetic energy of rolling sphere would be (in J)

Consider v to be the velocity of the sphere's centre. When rolling without sliding, the angular speed of the centre is equal to vr, where r is... View Article

A current of 1.40 ampere is passed through 500mL of 0.180M solution of zinc sulphate for 200 seconds. The molarity of Zn2+ ions after deposition of zinc is:

The equation is given by Zn2++ 2e− ⟶ Zn Faraday = Charge/96500 =1.40×200/96500 = 2.90×10−3 mol ∴Zn deposited =2.90×10−3/2 =1.45×10−3 mol Now,... View Article

Two resistors whose value are in ratio 2:1 are connected in parallel with one cell. Then ratio of power dissipated is

The heat developed is given by H = V2t/R ⇒ HHalf/Hfull = (RFull/RHalf) = R/R/2 = 2 Therefore, HHalf = 2 × HFull... View Article

A conducting rod of length l is hinged at point O. It is free to rotate in a vertical plane. There exists a uniform magnetic field B in horizontal direction. The rod is released from the position. What is the potential difference between the two ends of the rod is proportional to?

The gravitational potential decreases to increase the kinetic energy of the rod. The equation can be written as, mg 1/2sinθ =... View Article

The angle of dip at a place is δ. If the dip is measured in a plane making an angle θ with the magnetic meridian, the apparent angle of dip δ1 will be :

Let δ1 be the angle of dip when dip circle is in magnetic meridian tanδ1=V/H The dip circle when makes an... View Article

A photoelectric cell is illuminated by a point source of light 1m away. What happens when the source is shifted to 2m?

The intensity of light is exactly proportional to the number of photoelectrons released each second. The light source's intensity is I = 1/d2... View Article

An electron moves in a circle of radius of 1.0cm with a constant speed of 4.0106m/s, electric current at a point on the circle will be: (e=−1.6×10⁻¹⁹C)

Given that the radius of circle R=1.0cm. Speed of electron along the circular path=4.0×106m/s. Constant value of electron or charge... View Article

A bar magnet of magnetic moment M is placed in the magnetic field B. The torque acting on the magnet is:

A pair force is made up of two parallel forces that have the same magnitude but opposing directions and do not have the same path of action. A... View Article

If a wire of resistance R = 10ohm is stretched to double of its length, then new resistance will be:

The expression for the resistance of a wire is given as, R = ρ l/A where, ρ is the resistivity of a material. l is the length of wire.... View Article

Show on a graph, the variation of resistivity with temperature for a typical semiconductor.

The resistivity is given by: ρ=m/ne2τ where n= Number density of electrons τ= Relaxation time With the rise in temperature, the number density... View Article

A particle moves on a circle of radius r with centripetal acceleration as function of time as ac=k²rt² where k is a positive constant .Find the following quantities as a function of time at an instant. (A) The speed of the particle. (B) The tangential acceleration of the particle (C) the resultant acceleration and (D) Angle made by the resultant with tangential direction

Now we know that the magnitude of centripetal acceleration is given by, ac=v2/r where, v is the linear velocity of the particle and r is the... View Article

An atomic power nuclear reactor can deliver 300 MW. The energy released due to fission of each nucleus of uranium atom U²³⁸ is 170 MeV. The number of uranium atoms fissioned per hour will be:-

Nuclear Energy is the energy in the core of an atom. Where an atom is a tiny particle that constitutes every matter in the universe. Normally,... View Article

Five point charges, each of value +q are placed on five vertices of a regular hexagon of side L. What is the magnitude of the force on a point charge of value −q placed at the centre of the hexagon?

Among the five forces on five charges,2pairs (four) of forces are cancelled with each other since they are equal in magnitude and opposite in... View Article

On a 60km track, a train travels the first 30km with a speed of 30kmh−1 . How fast must the train travel the next 30km so as to average 40kmh−1 for the whole trip?

It is given that the first 30km is traveled with the speed 30kmh−1 , let us consider that the speed with which the next 30km is travelled... View Article

The mass of a non-volatile solute of molar mass 40g/mol that should be dissolved in 114g of octane to lower its vapour pressure by 20% is:

The pressure imposed by a gas on a liquid (or solid) in a closed system at a certain temperature is known as vapour pressure. When liquid... View Article

A bullet is fired from a gun, the force on the bullet is given by F=600−2×10⁵t where F is in newton and t in second. The force on the bullet becomes zero as soon as it leaves the barrel. What is the average impulse imparted to a bullet?

Force acting on the bullet is given as ⇒ F=600−2×105t ⇒ t=600/2×105 t = 3×10−3s Now impulse... View Article

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