Airforce Group X Quiz || Physics || Optics & Modern Physics for CDS & Defence Exams

Question 1

A transformer has an efficiency of 80%. It is connected to a power input of 4 kW and 100 V. if the secondary voltage is 240 V, then the secondary current is

Question 2

A sonometer wire resonates with a given tuning fork forming stationary waves with 5 antinodes, between 2 bridges, when a mass of 9 kg is suspended from the wire. When the mass is replaced by another mass m, the wire with the same tuning fork forms three antinodes, for the same position of the bridges. The value of m is

Question 3

The radius of curvature of spherical surface is 10 cm. The spherical surface separates two media of refractive indices μ₂ = 1.3 and μ₃ = 1.5 as shown in Figure. The medium of refractive index 1.3 extends upto 78 cm from the spherical surface. A luminous point object O is at the distance of 144 cm from the spherical surface in the medium of refractive index μ₁ = 1.1. The image formed by the spherical surface is at

Question 4

In a decay process A decays to B,

Two graphs of number of nuclei of A and B versus time is given ,then which of the following option is incorrect:

Question 5

The maximum current in a galvanometer can be 10 mA. It’s resistance is 10Ω. To convert it into an ammeter of 1 Amp. A resistor should be connected in

Question 6

A small circular wire loop of radius a is located at the centre of a much larger circular wire loop of radius b as shown above (b> >a). Both loops are coaxial and coplanar. The larger loop carries a time (t) varying current I = I₀ cos ωt where I₀ and ω are constants. The large loop induces in the small loop an emf that is approximately equal to which of the following.

Question 7

A point object is released at t = 0, from a point A (0, 24 m) as shown in the figure. The plane mirror is fixed at angle 45^o from vertical. Distance between the object and image will be