Physics Test - ...

The base current in a transistor circuit changes from 45μA to 140μA. Accordingly, the collector current changes from 0.2 mA to 4.00 mA. The gain in current is:

If one of the two electrons of a \(\mathrm{H}_{2}\) molecule is removed, we get a hydrogen molecular ion \(\mathrm{H}_{2}^{+}\). In the ground state of a \(\mathrm{H}_{2}^{+}\), the two protons are separated by roughly \(1.5 \mathring{A},\) and the electron is roughly \(1  \mathring{A}\) from each proton. Determine the potential energy of the system.

The electric field of a plane electromagnetic wave is given by:

\(\overrightarrow{\mathrm{E}}=\mathrm{E}_{0}(\hat{\mathrm{x}}+\hat{\mathrm{y}}) \sin (\mathrm{kz}-\omega \mathrm{t})\)

Its magnetic field will be given by:

A point object is placed at the focus of a convex mirror the image will be formed at:

The ratio of secondary of primary turns of step up transformer is 4 : 1. If a current of 4A is applied to the primary, the induced current in the secondary will be:

What type of energy radiates from hot objects and can be seen by cameras?

What is the expression for the Current Amplification factor?

What is the force between two small charged spheres having charges of \(2 \times 10^{-7} \mathrm{C}\) and \(3 \times 10^{-7} \mathrm{C}\) placed \(30 \mathrm{~cm}\).