The magnitudes of the electric field due to the two charges +q and -q are given by,

The directions of E+q and E-q are as shown in the figure. The components normal to the dipole axis cancel away. The components along the dipole axis add up.
Therefore, Total electric field.
E = - (E+q + E-q) cosθ p [Negative sign shows that field is opposite to p]


At large distances (r>>a),this reduces to

Electrical heating comes from the power dissipated in a resistor, given by P = I^2 * R (where P=power, I=current, R=resistance). Also, V=IR; this can be rearranged to state I=V/R. This can be substituted into the equation for power to state:
P = I^2 * R
=(V/R)^2 * R
=V^2/R
Power is inversely proportional to resistance at constant voltage. Therefore, for circuits connected to a constant voltage source (the 220 volt mains), the one with the lowest resistance will have the highest heat. If the toaster gets hotter, it has lower resistance. Hence, bulb will have higher resistance. 

On July 7, HRD Minister Ramesh Pokhriyal announced a major CBSE syllabus reduction with 30% of the syllabus slashed for the year 2020-21 for classes 9 to 12 because of the reduction in classroom teaching time due to the Covid-19 pandemic and lockdown.

CBSE has rationalized the syllabus with the help of suggestions from NCERT and the same has been notified by a new CBSE notification as well.

The CBSE syllabus has been reduced but care has been taken so that the learning outcomes remain the same and the students do not miss out on learning core concepts in various subjects.

However, CBSE stated in its notification that though 30% of the syllabus has been cut from the new academic year, teachers should ensure that students understand these topics so that they can use the information in connection with other topics.

It further stated that the deleted portions of the CBSE syllabus will not be included in the internal assessments or the year-end board exams.

Deleted syllabus of CBSE Class 12 Physics

Van de graaff generator is used to generate high voltages of the order of a few million volts. This results in generation of large electric fields for experimental purposes.

Principle

• The inner sphere has a higher potential than outer if the charge q is positive.
• If the two spheres are connected through a wire, the charge will flow from high to low potential.
• Thus, providing smaller potentials at the inner sphere will keep building large amount of charge at the outer sphere, till the breakdown field of air (3 x 10⁶ V/m) is reached.
• This accumulates close to millions of volts.

Construction

• A large spherical conducting shell (of few metre radius) is supported at a height several meters above the ground on an insulating column.
• A long narrow endless belt insulating material, like rubber or silk, is wound around two pulleys – one at ground level, one at the center of the shell.
• This belt is kept continuously moving by a motor driving the lower pulley.
• It continuously carries positive charge, sprayed on to it by a brush at ground level, to the top.
• There it transfers its positive charge to another conducting brush connected to the large shell.
• Thus positive charge is transferred to the shell, where it spreads out uniformly on the outer surface and a voltage difference of as much as 6 or 8 million volts (with respect to ground) can be built up.

On July 7, HRD Minister Ramesh Pokhriyal announced a major CBSE syllabus reduction with 30% of the syllabus slashed for the year 2020-21 for classes 9 to 12 because of the reduction in classroom teaching time due to the Covid-19 pandemic and lockdown.

CBSE has rationalized the syllabus with the help of suggestions from NCERT and the same has been notified by a new CBSE notification as well.

The CBSE syllabus has been reduced but care has been taken so that the learning outcomes remain the same and the students do not miss out on learning core concepts in various subjects.

However, CBSE stated in its notification that though 30% of the syllabus has been cut from the new academic year, teachers should ensure that students understand these topics so that they can use the information in connection with other topics.

Deleted syllabus of CBSE Class 12 Physics

Capacitor:

It is an arrangement of primarily two conductors for storing large amount of electric charge.  

Capacitance of a Capacitor:

Capacitance (C) of a capacitor is defined as ratio of charge (Q) given to the potential difference (V) applied across the conductors, i.e., C = Q/V.

The SI unit of capacitance is farad (F).

Suppose two long thin straight conductors (or wires) PQ and RS are placed parallel to each other in vacuum (or air) carrying currents I₁  and I₂ respectively. It has been observed experimentally that when the currents in the wire are in the same direction, they experience an attractive force and when they carry currents in opposite directions, they experience a repulsive force. Let the conductors PQ and RS carry currents I₁  and I₂ in same direction and placed at separation r. Consider a current–element ‘ab’ of length ΔL of wire RS. The magnetic field produced by current-carrying conductor PQ at the location of other wire RS

DALTON’S ATOMIC THEORY:

• Atoms are the smallest constituents of matter and can’t be divided further(indivisible)
• Atoms belonging to same matter have similar characteristics and mass; atoms of different matter have different properties and mass
• Atoms are reoriented in a chemical reaction (not generated or destructed)

The electron was the first fundamental particle that was discovered. The credit for the discovery of the electron and its properties goes to J.J. Thomson based on his experiments carried out in a discharge tube. He suggested that electrons are necessary constituents of all atoms. J.J. Thomson carried out experiments by taking a gas at low pressure of 0.01mm Hg in a discharge tube.

The British physicist Sir James Chadwick discovered neutrons in the year 1932. He was awarded the Nobel Prize in Physics in the year 1935 for this discovery.

The discovery of the proton is credited to Ernest Rutherford, who proved that the nucleus of the hydrogen atom (i.e. a proton) is present in the nuclei of all other atoms in the year 1917.

 All elements consists of very small invisible particles, called atom. Every atom is a sphere of radius of the order of 10^-10 m, in which entire mass is uniformly distributed and negative charged electrons revolve around the nucleus