Absorption coefficient of an ideal blackbody is :

(1) less then 1
(2) 1
(3) zero
(4) infinity

If in an experiment for determination of velocity of sound by resonance tube method using a tuning fork of 512 Hz, first resonance was observed at 30.7 cm and second was obtained at 63.2 cm., then maximum possible error in velocity of sound is

(1) 204.8 cm/sec
(2) 102.4 cm/sec
(3) 80 cm/sec.
(4) 161.3 cm/sec.

The charge on a 48 μF capacitor is increased from 0.1 C to 0.5 C. The energy stored in the capacitor increases  by

1) 250 J

2) 2500 J

3) 2.5×10⁶ J

4) 2.42×10⁻⁶ J 

For the circuit shown in figure, which of the following statement is true?

1) with S₁ closed V₁=15V, V₂ = 20 V

2) with S₃ closed V1=V₂ = 25 V

3) with S₁ and S₂ closed V₁ = V₂=0

4) with S₁ and S₃ closed V₁ = 30 V, V2=20 V

A cart on an air track is moving at 0.5 m/s when the air is suddenly turned off. The cart comes to rest after traveling 1 m. The experiment is repeated, but now the cart is moving at 1 m/s when the air is turned off. How far does the cart travel before coming to rest?

1) 1 m

2) Ö2 m

3) 2 m

4) 4 m

Two charges of 50μC and 100μC1 are separated by a distance of 0.6 m0.6 m. The intensity of electric field at a point midway between them is :

1) 50 ×10⁶V/m
2) 5 ×10⁶V/m
3) 10 ×10⁶V/m
4) 10 ×10^-6V/m

If the pressure of gas is increased from 1.01×10 ⁵ pa to 1.165×10⁵ pa and volume is decreases by 10% at constant temperature then the Bulk modulus of the gas is

(1) 15.5 × 10⁵ pa
(2) 1.4 × 10⁵ pa
(3) 1.55 × 10⁵ pa
(4) 0.0155 × 10⁵ pa

 A bullet with a mass of 10.0 grams and an initial speed of 800 m/s penetrates a distance 5 cm into a fixed block of wood before stopping. The average magnitude of the force exerted by the block on the bullet was

1) 1.3 x 10⁵ N        

2) 6.4 x 10⁵ N

3) 6.4 x 10⁴ N        

4) 1.3 x10³ N

A charged oil drop is suspended in a uniform field of 3 x 10⁴  v/m so that it neither falls nor rises. The charge on the drop will (Take the mass of the charge  = 9.9 x 10^-15 kg  and g = 10 m/s²  )

1) 1.25×10¹⁰C
2) 2.5×10¹⁰C
3) 3.3×10¹⁰ C
4) none

The electron in a hydrogen atom makes a transition n₁→n₂, where n₁ and n₂ are the principal quantum numbers of the two states. Assume the Bohr model as valid in this case. The frequency of the orbital motion of the electron in the initial state is 1 / 27 of that in the final state. The possible values of n₁ and n₂ are

1) n₁=6,n₂=3
2) n₁=4,n₂=2
3) n₁=8,n₂=1
4) n₁=3,n₂=1