MARCH 2024 — Physics STD 12 Science — Question

An electron and a proton are at a distance of 1. The moment of this dipole will be (C  X m)

(a) 1.6

(b) 1.6

(c) 3.2

(d) 3.2

The formation of a dipole is due to two equal and dissimilar point charges placed at a:

The wavelength of light visible to eye is of the order of

(a)

(b)  m

(c) 1 m

(d) 6  m

Time taken by the sunlight to pass through a window of thickness 4 mm whose refractive index is 1.5 is

(a) 2  sec

(b) 2 sec

(c) 2  sec

(d) 2   sec

In the figure a carbon resistor has bands of different colours on its body as mentioned in the figure.  The value of the resistance is

(a) 2.2 k W

(b) 3.3 k W

(c) 5.6 k W

(d) 9.1 k W

A gate in which all the inputs must be low to get a high output is called

(a) A NAND gate

(b) An inverter

(c) A NOR gate

(d) An AND gate

A magnet freely suspended in a vibration magnetometer makes 10 oscillations per minute at a place A and 20 oscillations per minute at a place B. If the horizontal component of earth’s magnetic field at A is 36 ,  then its value at B is

(a) 36 × 10–6 T

(b) 72 × 10–6 T

(c) 144 × 10–6 T

(d) 288 × 10–6 T

The half-life of radon is 3.8 days. Three forth of a radon sample decay in

(a) 5.02 days

(b) 15.2 days

(c) 7.6 days

(d) 11.4 days

The charge on a hole is equal to the charge of

(a) Zero

(b) Proton

(c) Neutron

(d) Electron

A thin prism  with angle 6° and made from glass of refractive index 1.54 is combined with another thin prism P₂ of refractive index 1.72 to produce dispersion without deviation. The angle of prism   will be

(a) 5° 24’

(b) 4° 30’

(c) 6°

(d) 8°