Nuclei — Physics STD 12 Science — Question

Heat of 80 J is produced in a conductor on passing a current of 2 A for 10 seconds. The resistance of conductor will be:

A ray of light falls on the surface of a spherical glass paper weight making an angle α with the normal and is refracted in the medium at an angle β. The angle of deviation of the emergent ray from the direction of the incident ray(a) (α  - β)(b) 2(α- β)(c) (α – β)/2(d) (β - α)

A galvanometer has a resistance of 25 ohm and a maximum of 0.01 A current can be passed through it.  In order to change it into an ammeter of range 10 A, the shunt resistance required is(a) 5/999 ohm(b) 10/999 ohm(c) 20/999 ohm(d) 25/999 ohm

If a bar magnet of magnetic moment M is freely suspended in a uniform magnetic field of strength B, the work done in rotating the magnet through an angle θ is(a) MB(1- sinθ(b) MB sinθ(c) MB cosθ(d) MB(1 – cosθ)

According to the quantum theory of light, the energy of light is carried in discrete units called:

Figure shows a charge q placed at the centre of a hemisphere. A second charge Q is placed at one of the positions A, B, C and D. In which position(s) of this second charge, the flux of the electric field through the hemisphere remains unchanged?

1. A
2. B
3. C
4. D

What is the effect on null deflection of galvanometer, when the radius of the wire is tripled?