NSO Class 12 Mock Test 2026 – Set 3

Sample 1, Logical Reasoning

Which of the following waves cannot be polarized?

1. A. Light waves
2. B. Radio waves
3. C. Sound waves in air
4. D. X-rays

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, how does the potential difference $V$ across the cell change?

1. A. It decreases linearly.
2. B. It increases linearly.
3. C. It increases non-linearly towards a limiting value $E$.
4. D. It remains constant at $E$.

Sample 3, Chemistry

What is the coordination number of cobalt in the complex $[Co(en)_2Cl_2]^+$, where 'en' stands for ethane-1,2-diamine?

1. A. 4
2. B. 5
3. C. 6
4. D. 3