A uniform rope of mass 0.1 kg and length 2.45 m hangs from a rigid support. The time taken by the transverse wave formed in the rope to travel through the full length of the rope is ______sec.

[Take g = 9.8 m/s²]

A square plate of 0.1 metre side moves parallel to a second plate with a velocity of 0.1 m/s, both plates being immersed in water. If the viscous force is 0.002 newton and the coefficient of viscosity is 0.01 poise, distance between the plates in metre is

An electric heater emits 1000 watt of thermal radiation. The coil has a surface area of 0.020m². Assuming that the coil radiates like a black body, then it’s temperature is _______ K 

A refrigerator, whose coefficient of performance K = 5, extracts heat from the cooling compartment at the rate of 250J/cycle. The work done per cycle to operate the refrigerator and the heat discharged per cycle to the room which acts as the high temperature reservoir are

At a given temperature the rms speed of oxygen molecules is 484 m/s. At the same temperature the rms speed of Helium molecules in m/s is (molecular wt. of oxygen= 32 and molecular wt. of He is 4)

A thin metallic spherical shell or radius r contains a charge Q on its surface. A point charge q₁ is placed at the centre of shell and another charge q₂ is placed outside the shell at a distance x from the centre. Then, the forces on charges q₁ and q₂ respectively are

A 12-pF capacitor is connected to a 50 V battery. The electrostatic energy is stored in the capacitor is ______x10^-8J.

Two unknown resistance are connected in the two gaps of a meter-bridge. The null point is obtained at 40 cm from the left end. A30Ω resistance is connected in series with the smaller of the two resistances, the null point shifts by 20 cm to the right end. What is the value of the smaller resistance (in Ω)?

The area of the coil in a moving coil galvanometer is 15cm² and has 20 turns. The magnetic induction is 0.2T and the couple per unit twist of the suspended wire is 10^-6 Mn per degree. If the deflection is 45^o, the current passing through it is ______x10^-4 A.

Two small magnets have their masses and lengths in the ratio 1 : 2. The maximum torques experienced by them in a uniform magnetic field are the same. For small oscillations, the ratio of their time period is