NSO Class 12 Mock Test 2026 – Set 1

Sample 1, Logical Reasoning

An electron enters a region of uniform magnetic field $\vec{B}$ with a velocity $\vec{v}$ perpendicular to the field. What is the work done by the magnetic field on the electron after it completes one half of a revolution?

1. A. $\pi m v^2$
2. B. $2 m v^2$
3. C. Zero
4. D. $\frac{1}{2} m v^2$

Sample 2, Physics

A cell of emf $E$ and internal resistance $r$ is connected across a variable external resistor $R$. As the resistance $R$ is increased from zero, which of the following graphs correctly represents the variation of potential difference $V$ across the resistor?

1. A. V increases linearly with R.
2. B. V decreases exponentially with R.
3. C. V increases and approaches a maximum value E asymptotically.
4. D. V remains constant at E.

Sample 3, Chemistry

Which of the following coordination entities is expected to exhibit optical isomerism?

1. A. trans-[Co(NH3)4Cl2]+
2. B. cis-[Co(en)2Cl2]+
3. C. trans-[Co(en)2Cl2]+
4. D. [Co(NH3)5Cl]2+