A 9 V battery has an internal resistance of 12 Ω. The potential difference across its terminals when it is supplying a current of 50 mA is

1. 8.94 V
2. 8.4 V
3. 9.06 V
4. 9.6 V

Assertion: The current is the rate of flow of charges.

Reason: Electric current will not flow between two charged bodies having same potential when connected.

1. Both Assertion and Reason are true.
2. Both Assertion and Reason are false.
3. Assertion is false but Reason is true.
4. Assertion is true but Reason is false

Sound energy passing per second through a unit area held perpendicular it is called

1. intensity
2. frequency
3. amplitude
4. quality

What is the magnification of the image when a lens of focal length 10 cm and object distance from the lens is 15 cm?

1. 2
2. 1
3. $\dfrac{1}{2}$
4. 4