Electric Charges and Fields — Physics STD 12 Science — Question

A wooden object floats in water kept in a beaker. The object is near a side of the beaker. Let P₁, P₂, P₃ be the pressures at the three points A, B and C of bottom as shown in the figure.

1. P₁ = P₂ = P₃
2. P₁ < P₂ < P₃
3. P₁ > P₂ > P₃
4. P₂ = P₃ ≠ P₁

When no current is passed through a conductor:

1. The free electrons do not move.
2. The average speed of a free electron over a large period of time is zero.
3. The average velocity of a free electron over a large period of time is zero.
4. The average of the velocities of all the free electrons at an instant is zero.

When a current I is passed through a wire of constant resistance, it produces a potential difference V across its ends. The graph drawn between log I and log V will be

(a)

(b)

(c)

(d)

Charge is:

What will be the angular width of central maxima in Fraunhoffer diffraction when light of wavelength 6000   is used and slit width is 12 

(a) 2 rad

(b) 3 rad

(c) 1 rad

(d) 8 rad

A beam of electron is used in an YDSE experiment. The slit width is d. When the velocity of electron is increased, then

(a)  No interference is observed	(b) Fringe width increases
(c)  Fringe width decreases	(d) Fringe width remains same

The correct equation of nuclear fusion reaction is:

Young's experiment establishes that

(a) Light consists of waves

(b) Light consists of particles

(c) Light consists of neither particles nor waves

(d) Light consists of both particles and waves

Two conducting circular loops F and G are kept in a plane on either side of a straight current-carrying wire as shown in the figure below.
If the current in the wire decreases in magnitude, the induced current in the loops will be:

Vertical component of earth's magnetic field is zero: