Electrostatic Potential and Capacitance — Physics STD 12 Science — Question

A series combination of two resistors 1 W each is connected to a 12 V battery of internal resistance 0.4 W.  The current flowing through it will be

(a) 3.5 A

(b) 5 A

(c) 6 A

(d) 10 A

In photoelectric effect, electrons are ejected from metals,if the incident light has a certain minimum?

An electromagnetic waves can be produced, when charge is:

If an electron revolves in the path of a circle of radius of 0.5  m at frequency of 5 × 10¹⁵ cycles/s the electric current in the circle is (Charge of an electron = 1.6 × 10^–19 C )

(a) 0.4 mA

(b) 0.8 mA

(c) 1.2 mA

(d) 1.6 mA

The ratio of contributions made by the electric field and magnetic field components to the intensity of an EM wave is:

The sensation of vision in the retina is carried to the brain by

(a) Ciliary muscles

(b)  Blind spot

(c) Cylindrical lens

(d)  Optic nerve

Which of the following statements about the behaviour of light is not correct?

Which of the following mirrors always forms a virtual and small image?

The energy of a hydrogen atom in its ground state is -13.6eV. The energy of the level corresponding to the quantum number n = 2 (first excited state) in the hydrogen atom is

(a) – 2.72 eV

(b) – 0.85 eV

(c) – 0.54 eV

(d) – 3.4 eV

Which of the following is not a consequence of Gauss’s law?