Electric Charges and Fields — Physics STD 12 Science — Question

Which of the following statement is true  

(a) Velocity of light is constant in all media

(b) Velocity of light in vacuum is maximum

(c) Velocity of light is same in all reference frames

(d) Laws of nature have identical form in all reference frames

In a meter bridge, the balancing length from the left end (standard resistance of one ohm is in the right gap) is found to be 20 cm. The value of the unknown resistance is

(a) 0.8 Ω

(b) 0.5 Ω

(c) 0.4 Ω

(d) 0.25 Ω

Capacitance (in F) of a spherical conductor with radius 1m is

(a) 1.1

(b)

(c) 9 ×

(d)

A convex mirror of focal length f forms an image which is   times the object. The distance of the object from the mirror is

(a) (n – 1)f

(b)

(c)

(d) (n + 1)f

The magnitude of which of the following is proportional to the frequency of the wave?

The graph between the instantaneous concentration (N)  of a radioactive element and time (t)  is

(a)

(b)

(c)

(d)

A hydrogen atom in its ground state absorbs 10.2 eV of energy. The orbital angular momentum is increased by

(a) 1.05   J-sec

(b) 3.16   J-sec

(c) 2.11   J-sec

(d) 4.22   J-sec

If the capacitors having capacitance C₁ and C₂ are connected in series then their resultant capacitance is given by:

The energy of characteristic X-ray is a consequence of which of the following?

If all the resistors shown have the value 2 ohm each, the equivalent resistance over AB is

(a) 2 ohm

(b) 4 ohm

(c) 1

(d) 2