For Fleming’s left-hand rule, write down the three things that are 90° to each other, and next to each one write down the finger or thumb that represents it.

1. Current – direction of center finger. 2. Magnetic field – direction of fore finger. 3. Force or Motion – direction of thumb.

For Fleming’s left-hand rule, write down the three things that ar…

Which of the two has a branched chain: isobutane or normal butane?

→

State one use of bleaching powder (other than bleaching).

→

How does the presence of impurities in a metal affect its resistance?

→

What type of bonds are present in methane $\left( CH _4\right)$ and sodium chloride $( NaCl )$ ?

→

Name the element whose allotropic form is graphite.

→

Name the functional group present in an organic compound which gives brisk effervescence with $NaHCO _3$.

→

Name the gas evolved when dilute HCl reacts with sodium hydrogencarbonate. How is it recognised?

→

What changes are seen in girls at the time of puberty?

→

Explain why, fertilisation is possible if mating takes place during the middle of menstrual cycle.

→

Name the indicator which can give us an idea of how strong or weak an acid or base is.

→