Variances

Hi, I am very confused about the variances topic.

Are these all the variances we need to know for the exam? If I am missing any please let me know.

Variances:

Selling price variance
Sales volume variance: 1) Capacity variance 2) Efficiency variance
Materials variances: 1) Material Price Variance 2) Material usage variance
Labour total variance: 1) Labour Price variance 2) Labour rate variance 3) Labour efficiency variance
Variable overheads variance: 1) Expenditure 2) Efficiency
Fixed overheads expenditure variance

Mix and yield variances
Idle time variances: 1) Rate of pay variance 2) Idle time variance 3) Efficiency variance

Regards,
Bhavik