# Posts by Judish

Total # Posts: 4

**Physics**

If the circle and square have the same area, then magnetizing force at the center of the coil as a result of current flowing through the coil will be in the ratio

**Physics**

A solenoid with a nickel core has 1000 turns on 0.5 m. The cross-sectional area of turn is 50 cm2. What is the magnetic field energy when a current 10 A passes through it ? Given permeability of nickel is 200.

**Physics**

Two transparent media F and G are separated by a plane boundary. The speed of light in medium F is 2.0x108 m/sec and in medium G is 2.5x108 m/sec. The critical angle for which a ray of light from F to G is totally internally reflected is

**Physics**

A 30 meter wide canal is flowing at the rate of 20 m/min. A boy can swim at the rate of 25 m/min in still water. The time taken by him to cross the canal perpendicular to the flow is