Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

The energy of a charged capacitor resides in

(a) The electric field only	(b) The magnetic field only
(d) Neither in electric nor magnetic field	(d) Neither in electric nor magnetic field

If an electron enters a magnetic field with its velocity pointing in the same direction as the magnetic field, then

(a) The electron will turn to its right

(b) The electron will turn to its left

(c) The velocity of the electron will increase

(d) The velocity of the electron will remain unchanged

Two condensers of capacity 0.3 μF  and 0.6 μF  respectively are connected in series. The combination is connected across a potential of 6 volts . The ratio of energies stored by the condensers will be         

(a)

(b) 2

(c)

(d) 4

A bar magnet of magnetic moment M is cut into two parts of equal length. The magnetic moment of either part is :

The resistance of a heater coil is 110 ohm. A resistance R is connected in parallel with it and the combination is joined in series with a resistance of 11 ohm to a 220 volt main line. The heater operates with a power of 110 watt. The value of R in ohm is

(a) 12.22	(b) 24.42
(c) Negative	(d) That the given values are not correct

Which of the following statement(s) is/(are) correct

(a) The rest mass of a stable nucleus is less than the sum of the rest masses of its separated nucleons

(b) In nuclear fission, energy is released by fragmentation of a very heavy nucleus

(c) The rest mass of a stable nucleus is greater than the sum of the rest masses of its separated nucleons.

(d) a, b

In the diagram, three point charges (labeled 1, 2 and 3) are shown, along with the electric field around them. Which charge(s) is/ are positive?

If  millimho, then on increasing plate voltage by  50 V, how much the grid voltage is changed so that plate current remains the same

(a) – 2.86 V

(b) –  4 V

(c) + 4 V

(d) + 2 V

A truth table is given below. Which of the following has this type of truth table

(a) XOR gate

(b) NOR gate

(c) AND gate

(d) OR gate

In an electron gun, the electrons are accelerated by the potential V.  If e is the charge and m is the mass of an electron, then the maximum velocity of these electrons will be

(a)

(b)

(c)

(d)