Which quantity remains conserved as external torque is zero :

(1) linear momentum

 A conventional electric current flows due east in a high voltage power line. What would be the direction of the resulting magnetic field directly below the power line?

1) north
2) east    
3) south    
4) west

Two oscillators are started simultaneously in same phase. After 50 oscillations of one, they get out of phase by π, that is half oscillation. The percentage difference of frequencies of the two oscillators is nearest to:

1) 2%
2) 1%
3) 0.5%
4) 0.25%

 A 240-Volt appliance draws 15A of current for a period of 2 hours. How much energy in kilowatt-hours does it consume?

1) 7.2

2) 2 .6 x10⁷ 

3) 7200

4) 3600

 Absorption coefficient of an ideal blackbody is :

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

A rod of 10cm length is moving perpendicular to uniform magnetic field of intensity 5×10⁻⁴Wb/m². If the acceleration of the rod is 5m/s² then the rate of increase of induced emf is

1) 2.5 × 10⁻⁴Vs⁻¹
2) 25 × 10⁻⁴Vs
3) 20 × 10⁻⁴Vs
4) 20 × 10⁻⁴Vs⁻¹

Block of mass 4 kg rests on a rough inclined plane making an angle of 30 with the horizontal. The coefficient of static friction between the block and the plane is 0.7. The friction force on the block is:
1. 9.8 N
2. 13.5 N
3. 16.8 N
4.19.6 N

Below the surface of a liquid the pressure acting in the liquid
 
 (1) Decreases as the depth increases
 (2) Increases as the depth increases
 (3) Is independent of the depth
 (4) Is the same for all liquids at a particular depth

An AC source of angular frequency ωω is fed across a resistor R and a capacitor C in series. The current registered is I. If now the frequency of source is changed to ω/3 (but maintaining the same voltage), the current in the circuit is found to be halved. The ratio of reactance to resistance at the original frequency ω is

1) $$\sqrt{\dfrac{3}{5}}$$
2) $$\sqrt{\dfrac{5}{3}}$$
3) $$\dfrac{3}{5}$$
4) $$\dfrac{5}{3}$$

 If light ray is reflected from the denser medium, the path difference produced in the reflected ray will be :

(1) λ/4

(2) λ/2

(3) λ

(4) zero