# Physics - Light Questions Answers

1. An electric lamp whose resistance is 10 ohm, and a conductor of 2 ohm resistance are connected in series with a 6 V battery. The total current through the circuit and the potential difference across the electric lamp are

• A. 3.6A,6V  • B. 0.5A,5V  • C. 2.0 A, 0.2 V  • D. 0.3 A, 3 V  2. Which one of the following phenomena cannot be attributed to the refraction of light?

• A. Twinkling of stars  • B. Mirage  • C. Rainbow  • D. Red shift  • Option : D
• Explanation : (D) Red shift is a phenomenon not attributed to the refraction of light.

3. The relation among u, v and f for a spherical mirror is (NTSE Mizoram, Stage-I, 2012-13)

• A. f = uv/(u + v)  • B. v = fu/(u + f)  • C. u = fv/(f + v)  • D. All of these  4. If the rays constituting the beam actually meet at a point or appear to meet at a point, then the beam is (NTSE Mizoram, Stage-I, 2012-13)

• A. Divergent  • B. Convergent  • C. Parallel  • D. Equal  5. What is the power of a concave lens whose focal length is -75.0 cm? (NTSE Mizoram, Stage-I, 2012-13)

• A. 1.33 D  • B. -13.3 D  • C. 13.3 D  • D. -1.33 D  