Alternating Current — Physics STD 12 Science — Question

What is the equivalent resistance between A and B in the figure below if R = 3Ω

(a) 9 Ω

(b) 12 Ω

(c) 15 Ω

(d) None of these

The materials having high resistance to the passage of electricity are called as:

If f_a and f_f represent the carrier wave frequencies for amplitude and frequency modulations respectively, then

(a)

(b)

(c)

(d)

Two thin lenses whose powers are +2D and –4D respectively combine, then the power of combination is

(a) – 2D

(b) + 2D

(c) – 4D

(d) + 4D

Two ions have equal masses but one is singly-ionised and the other is doubly-ionised. They are projected from the same place in a uniform magnetic field with the same velocity perpendicular to the field.

1. Both ions will move along circles of equal radii.
2. The circle described by the singly-ionised charge will have a radius that is. double that of the other circle.
3. The two circles do not touch each other.
4. The two circles touch each other.

A charge of magnitude 3e  and mass 2m is moving in an electric field . The acceleration imparted to the charge is

(a) 2Ee/3m

(b) 3Ee/2m

(c) 2m/3Ee

(d) 3m/2Ee

Which of the following is a fusion reaction?

In a series LCR circuit, the voltage across the resistance, capacitance and inductance is 10 V each. If the capacitance is short circuited the voltage across the inductance will be

M_x and M_y denote the atomic masses of the parent and the daughter nuclei respectively in a radioactive decay. The Q-value for a β^- decay is Q₁ and that for a β⁺ decay is Q₂. If me denotes the mass of an electron, then which of the following statements is correct?

Which of the following pairs is an isobar

(a)  and

(b)  and

(c)  and

(d)  and