Magnetic Effects of Electric Current — Science STD 10 — Question

Keeping the potential difference constant, the resistance of a circuit is doubled. The current will become:

Which of the following statement is correct:

Identify the incorrect statement: Magnetic field lines due to a circular coil is:

Ohm's law gives a relationship between:

1. Current and resistance.
2. Resistance and potential difference.
3. Potential difference and electric charge.
4. Current and potential difference.

A glass slab is placed over a page on which the word VIBGYOR is printed with each letter in corresponding colour. Then, which of the following is correct?

Inability of the eye to focus on both far and near objects with advancing age is:

Refraction of light in the eye occurs at:

To obtain a magnification of, -0.5 with a convex lens, the object should be placed:

1. At F
2. Between optical centre and F.
3. Between F and 2F.
4. Beyond 2F.

Which of the following is a natural phenomenon which is caused by the dispersion of sunlight in the sky?

If a magnification of, -1 is to be obtained by using a converging lens of focal length 12cm, then the object must be placed:

1. Within 12cm.
2. At 24cm.
3. At 6cm.
4. Beyond 24cm.