Current Electricity — Physics STD 12 Science — Question

Two identical charged spherical drops each of capacitance C merge to form a single drop. The resultant capacitance is(a) Equal to 2C (b) Greater than 2C (c) Less than 2C but greater than C(d) Less than C

Assertion   :   Separation of isotope is possible because of the difference in electron numbers of isotope.
Reason       : Isotope of an element can be separated by using a mass spectrometer. (a) If both assertion and reason are true and the reason is the correct explanation of the assertion.(b) If both assertion and reason are true but reason is not the correct explanation of the assertion.(c) If assertion is true but reason is false.(d) If assertion is false but reason is true.

The sun emits a light with maximum wavelength 510 mm while another star X emits a light with maximum wavelength of 350 nm. What is the ratio of surface temperature of sun and the star X (a) 2.1(b) 0.68(c) 0.46(d) 1.45

When a p-n diode is reverse biased, then

If the direction of the initial velocity of a charged particle is neither along nor perpendicular to that of the magnetic field, then the orbit will be:

Vibration magnetometer works on the principle of(a) Torque acting on the bar magnet(b) Force acting on the bar magnet(c) Both the force and the torque acting on the bar magnet(d) None of these

What is the range of the characteristic impedance of a coaxial cable?

Ray optics is valid when characteristic dimensions are:

Which of the following is an example of a molecule whose centre of mass of positive and negative charges coincide each other?