If the strength of the current flowing through a wire is increased, the strength of the magnetic field produced by it:

1. decreases
2. increases
3. remains the same
4. first increases then decreases

Choose the correct relation for e.m.f. (ε) and terminal voltage V:

1. ε = V [always]
2. V > ε [always]
3. V < ε [when the cell is in use]
4. None of these

When a ray of light travels normal to the given surface, then the angle of refraction is:

1. 180°
2. 90°
3. 0°
4. 45°

Specific heat capacity of a substance X is 1900 Jkg^-1°C^-1 means:

1. Substance X absorbs 1900 J for 1°C rise in temperature
2. 1 kg of substance X absorbs 1900 J heat for 1°C rise in temperature
3. 1 kg of substance X absorbs 1900 J heat to increase the temperature
4. 1 kg of substance X absorbs 1900 J heat to cool down by 1°C