Moving Charges and Magnetism — Physics STD 12 Science — Question

Can electric field at a point be zero, while electric potential is not zero?

An electron does not suffer any deflection while passing through a region of uniform magnetic field. What is the direction of the magnetic field?

A battery of constant voltage is connected to the diametrically opposite ends of a circular coil. What is magnetic field at the center of the coil?

Calculate the volume of 1 mole of an ideal gas at STP.

Using the concept of force between two infinitely long parallel current carrying conductors, define one ampere of current.

Why is it easier to swim in sea water than in fresh water?

A carbon resistor is marked in colour bands of red, black, orange and silver. What is the resistance and tolerance value of the resistor?

Two equal point charges are placed at a dis- tance of 1 meter from each other, experience a force of 8N. If these charges are kept in water at the same distance, then how much force will be felt between them?

At Deoprayag (Garhwal, UP) river Alaknanda mixes with the river Bhagirathi and becomes river Ganga. Suppose Alaknanda has a width of 12m, Bhagirathi has a width of 8m and Ganga has a width of 16m. Assume that the depth of water is same in the three rivers. Let the average speed of water in Alaknanda be 20km/h and in Bhagirathi be 16km/h. Find the average speed of water in the river Ganga.

When light travels from a rarer to a denser medium, the speed decreases. Does this decrease in speed imply a decrease in the energy carried by the light wave? Justify your answer.